PROSPECTUS SUMMARY

        This summary highlights some of the information contained in this prospectus and does not contain all of the information that may be important to you. You should read this entire prospectus and the documents to which we refer you before making an investment decision. You should carefully consider the information set forth under "Risk Factors," "Cautionary Statement Regarding Forward-Looking Statements" and "Management's Discussion and Analysis of Financial Condition and Results of Operations" and the historical consolidated financial statements and the related notes to those financial statements included elsewhere in this prospectus. Where applicable, we have assumed an initial public offering price of $40.00 per share (the midpoint of the price range set forth on the cover page of this prospectus). Unless otherwise indicated, the information presented in this prospectus assumes that the underwriters' options to purchase additional shares of common stock are not exercised. Unless otherwise indicated, the estimated reserve volumes presented in this prospectus are based on SEC pricing at June 30, 2013 (assuming ethane rejection), as described in "—Our Properties—Reserves." Certain operational terms used in this prospectus are defined in the "Glossary of Natural Gas and Oil Terms."

        In this prospectus, references to "we," "us," "our" and the "Company" refer to Antero Resources LLC and its subsidiaries before the completion of our corporate reorganization and to Antero Resources Corporation and its subsidiaries as of and following the completion of our corporate reorganization. Please see "Corporate Reorganization." References to the "selling stockholder" refer to Antero Resources Investment LLC.

Our Company

        We are an independent oil and natural gas company engaged in the exploitation, development and acquisition of natural gas, NGLs and oil properties located in the Appalachian Basin in West Virginia, Ohio and Pennsylvania. We are focused on creating shareholder value through the development of our large portfolio of repeatable, low cost, liquids-rich drilling opportunities in two of the premier North American shale plays. We currently hold approximately 329,000 net acres in the southwestern core of the Marcellus Shale and approximately 102,000 net acres in the core of the Utica Shale. In addition, we estimate that approximately 170,000 net acres of our Marcellus Shale leasehold are prospective for the slightly shallower Upper Devonian Shale. Finally, we own the deep rights on a portion of our Marcellus Shale acreage in West Virginia that we believe is prospective for the dry gas Utica Shale. As of June 30, 2013, our estimated proved, probable and possible reserves were 6.3 Tcfe, 14.0 Tcfe and 7.4 Tcfe, respectively, and our proved reserves were 23% proved developed and 91% natural gas, assuming ethane rejection. As of June 30, 2013, our drilling inventory consisted of 4,576 identified potential horizontal well locations, approximately 64% of which are liquids-rich drilling opportunities.

        Our management team has a proven track record of implementing geologically driven growth strategies in some of the most prominent unconventional plays across the United States, including the Barnett, Woodford, Marcellus and Utica Shales. Paul Rady, our Chairman and Chief Executive Officer, and Glen Warren, our President and Chief Financial Officer, founded our business in 2002. The majority of our management team has worked together at various times for over 30 years at Amoco Production Company, Barrett Resources Corporation, Pennaco Energy Inc. and Antero Resources. Our management team has created significant shareholder value through various past ventures, including the sale of two unconventional resource-focused upstream companies and one midstream company in the last 15 years.

        We have been successful in targeting large, repeatable resource plays where horizontal drilling and advanced fracture stimulation technologies provide the means to economically develop and produce natural gas, NGLs and oil from unconventional formations. We have been early adopters of innovative hydraulic fracturing and completion techniques, having drilled over 450 horizontal wells in the Barnett, Woodford, Marcellus and Utica Shales. As a result of our horizontal drilling and completion expertise, and the predictable geologic structure throughout our largely contiguous land position in the

southwestern core of the Marcellus Shale, we have drilled approximately 1.3 million lateral feet without encountering any faulting in our target zone. We have drilled and completed 199 horizontal wells in the Marcellus Shale with a 100% success rate to date. We define the term 100% success rate to mean that all wells were completed and produce in commercially viable quantities. With 15 rigs running, we are currently the most active driller in the Marcellus Shale based on information from RigData. We have begun to apply the expertise and approach we employ in the Marcellus Shale to the Utica Shale, and we believe we will be able to achieve similar success. We have drilled and completed 11 horizontal wells in the Utica Shale with a 100% success rate without encountering any faulting.

        Our net daily production in the second quarter of 2013 averaged 458 MMcfe/d, including 4,160 Bbls/d of NGLs and oil. Further, our estimated average net daily production for the month of August 2013 was 594 MMcfe/d, including 8,630 Bbls/d of NGLs and oil. We grew proved reserves at a compounded annual growth rate of 96% from 2006 to 2012, despite the 2012 divestiture of our Arkoma and Piceance Basin properties. Additionally, from January 1, 2012 to June 30, 2013, we increased our Appalachian proved reserves by 47% to 6.3 Tcfe, assuming ethane rejection at each date.

        The charts below illustrate the growth in our average net daily production on an overall basis since 2006 and in the Appalachian Basin since 2010:

Antero Average Net Daily Production		Antero Appalachian Basin Average Net Daily Production

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        Our 2013 capital budget is $2.45 billion, including $1.45 billion for drilling and completion, substantially all of which is allocated to our operated drilling in liquids-rich gas areas. As of June 30, 2013, we had spent approximately $1.2 billion of our 2013 capital budget.

Our Properties

Marcellus Shale

        We believe that the Marcellus Shale is a premier North American shale play due to its high well recoveries relative to drilling and completion costs, broad aerial extent, relatively homogeneous high-quality reservoir characteristics and significant hydrocarbon resources in place. Based on these attributes, as well as drilling results publicly released by other operators, we believe that the Marcellus Shale offers some of the most attractive single-well rates of return of all North American conventional and unconventional play types. We also believe that the Marcellus Shale has two core areas: the southwestern core in northern West Virginia and southwestern Pennsylvania and the northeastern core in northeastern Pennsylvania. According to RigData, as of September 2013, approximately 90% of the 91 drilling rigs operating in the Marcellus Shale were located in these two core areas.

        All of our approximately 329,000 net acres in the Marcellus Shale are located within the southwestern core. We have experienced virtually no geologic complexity in our drilling activities to date, which has contributed to what we believe to be a narrow and predictable band of expected well recoveries per 1,000 feet of lateral length on our wells. Further, the lower thermal maturity of the Marcellus Shale in the western half of the southwestern core yields liquids-rich natural gas and condensate, which allows for NGL processing that can significantly improve well economics. As of June 30, 2013, we had approximately 2,941 identified gross undrilled horizontal well locations in the Marcellus Shale.

        For the three months ended June 30, 2013, we had average net daily production of 457 MMcfe/d in the Marcellus Shale. Further, our estimated average net daily production for the month of August 2013 in the Marcellus Shale was 549 MMcfe/d, including 6,528 Bbls/d of NGLs and oil. We currently have 15 rigs operating in the Marcellus Shale and expect to drill 135 wells in 2013, of which 74 had been drilled as of June 30, 2013. We believe our full cycle drilling, completion and operating costs on a per unit basis are among the lowest in the Marcellus Shale and the industry as a whole.

Utica Shale

        Based on initial drilling results and the first two months of production for our 11 Utica wells, we believe that the Utica Shale is a premier North American shale play. We believe that the core area is located in the southern portion of the play, which has been defined by significant drilling activity by several operators. We own approximately 102,000 net acres in the core of the Utica Shale and expect to add to our sizeable land position. The proximity of our Utica acreage position to our operations in the Marcellus Shale allows us to capitalize on operating and midstream synergies. We are currently operating four drilling rigs in the Utica Shale and have completed 11 horizontal wells with strong results. We have had a 100% success rate and believe over 90% of our acreage has liquids-rich gas processing potential. We expect to drill 26 wells in the Utica Shale in 2013, of which 11 had been drilled as of June 30, 2013. As of June 30, 2013, we had approximately 720 identified gross undrilled horizontal well locations in the Utica Shale. For the three months ended June 30, 2013, we had average net daily production of 1 MMcfe/d in the Utica Shale. Further, our estimated average net daily production for the month of August 2013 in the Utica Shale was 45 MMcfe/d, including 2,102 Bbls/d of NGLs and oil.

Reserves

        The following tables provide summaries of our estimated reserves as of June 30, 2013, assuming ethane "recovery" and ethane "rejection." Ethane rejection occurs when ethane is left in the wellhead gas stream when the gas is processed, rather than being separated out and sold as a liquid after fractionation. When ethane is left in the gas stream, the BTU content of the residue gas at the outlet of the processing plant is higher. Producers will elect to "reject" ethane when the price received for the higher BTU residue gas is greater than the price received for the ethane being sold as a liquid after fractionation. When ethane is recovered, the BTU content of the residue gas is lower, but a producer is then able to recover the value of the ethane sold as a separate NGL product. In addition, gas processing plants can produce the other NGL products (propane, normal butane, isobutane and natural gasoline) while rejecting ethane. The combination of infrastructure constraints in the Appalachian region and low ethane prices has resulted in many producers "rejecting" rather than "recovering" ethane. Although our reserve data as of December 31, 2012 assumed ethane recovery based on the reserve pricing methods required by the SEC, or SEC pricing, the current spot price environment has shifted to one that favors ethane rejection and therefore our reserve estimates as of June 30, 2013 assumed ethane rejection.

SEC Pricing

Strip Pricing Sensitivity Case

Operating Data

        The following table provides a summary of our net acreage and identified potential well locations as of June 30, 2013, our 2013 and 2014 projected drilling schedules based on gross wells, and our average net daily production for August 2013:

Recent Operating Developments

        Our estimated current net daily production is 640 MMcfe/d, including 11,500 Bbls/d of NGLs and oil. Our estimated current net daily production in the Marcellus Shale is 555 MMcfe/d, including 7,400 Bbls/d of NGLs and oil, and our estimated current net daily production in the Utica Shale is 85 MMcfe/d, including 4,100 Bbls/d of NGLs and oil. Current net daily production represents the average net daily production for the period from September 1, 2013 through September 25, 2013.

Midstream Infrastructure

        We maintain a strong commitment to developing the necessary midstream infrastructure to support our drilling schedule and production growth. We accomplish this goal through a combination of internal asset developments and contractual relationships with third-party midstream service providers. As part of our internal developments, we have invested a significant amount of capital in building low- and high-pressure gathering lines, compression facilities and water pipeline systems. We currently own and operate 103 miles of gathering pipelines and have contracted access to an additional 94 miles of gathering pipelines in the Marcellus and Utica Shales. We also own and operate four compressor stations and have firm access to nine additional third-party compressor stations in the Appalachian

Basin. We have additional gathering pipelines and compressor stations under construction to support our planned drilling activities in the Marcellus and Utica Shales. In the past we have monetized certain midstream infrastructure assets for a significant return on investment and redeployed the proceeds into our ongoing operations.

        Through third-party contractual relationships, we have obtained committed cryogenic processing capacity for our Marcellus and Utica Shale production. For example, we have contracted with MarkWest Energy Partners, L.P., or MarkWest, to provide processing capacity as follows:

        Our NGL processing capacity at the Sherwood facility has been curtailed since August 2013 due to a line break in a MarkWest NGL pipeline caused by a landslide due to abnormal rainfall. Repairs and remediation to the pipeline and rights of way in the landslide impacted areas are currently underway, and MarkWest is working to return the pipeline to service, which is expected to be in October 2013. While our NGLs from that facility are being transported by truck for fractionation and sale, we estimate that our net daily production since August 2013 has been reduced by 60 to 80 MMcfe/d as a result of this line break in order to match NGL production to trucking capacity. We do not expect the temporary NGL processing capacity constraints at the Sherwood facility to have a material impact on our results of operations.

        Our midstream infrastructure also includes two independent fresh water sourcing and delivery systems for well completion operations in our Marcellus and Utica Shale operating areas. These systems consist of permanent buried pipelines, temporary surface pipelines and fresh water storage facilitates, as well as pumping stations to transport the fresh water throughout the pipeline networks. Current cost estimates for both the Marcellus and Utica projects are anticipated to total $525 million through 2023. The capital expenditures are estimated to be $250 million in 2013. The water pipeline

systems are expected to deliver a reliable year-round water supply, lessen water handling costs and significantly decrease water truck traffic and associated road damage on state, county and municipal roadways. It is estimated that these water pipeline systems will reduce our well completion costs by up to $600,000 per well, and we anticipate that over 30% of our 2013 completed wells and up to 90% of our 2014 completed wells will utilize these new infrastructures. Assuming a 7,000 foot horizontal well lateral, it is estimated that 1,850 water truckload trips per well completion will be eliminated from roadways.

        We also have contracted 1,300,000 MMBtu/d of long-haul firm transportation or firm sales capacity on various pipelines and 20,000 Bbl/d of committed ethane takeaway capacity to accommodate our growing production and manage basis differentials.

        We will continue to invest significantly in our midstream infrastructure, as it allows us to optimize our processing and takeaway capacity to support our expected rapid production growth, affords us more control over the direction and planning of our drilling schedule and has historically created significant value for our equity owners. In 2013, we estimate we will spend a total of approximately $600 million on midstream infrastructure.

        In addition, we believe that our midstream assets may be well suited for a master limited partnership ("MLP") or similar structure. Accordingly, following the closing of this offering, we intend to contribute our midstream assets to Antero Resources Midstream LLC, or Antero Midstream, a subsidiary formed to hold our midstream business, and enter into commercial arrangements for midstream services with them. We will initially own all of the membership interests in Antero Midstream other than a special membership interest, which will be indirectly owned by Antero Investment. The special membership interest in Antero Midstream will provide Antero Investment with certain rights, including the right to cause an initial public offering of Antero Midstream as a MLP or similar structure. Following any such initial public offering, the special membership interest will convert into a general partner interest and incentive distribution rights in the MLP, which will allow Antero Investment to manage Antero Midstream's business and affairs. We may also seek opportunities to finance our midstream business on a stand-alone basis. See "Certain Relationships and Related Party Transactions—Antero Midstream" and "Corporate Reorganization."

Business Strengths

        Our objective is to build shareholder value through growth in reserves, production and cash flows by developing and expanding our portfolio of low-risk, high-return drilling locations and ensuring timely development of processing and pipeline takeaway capacity. We believe that the following strengths will allow us to successfully execute our business strategies:

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Large, stable operated position in the core of the Marcellus and Utica Shales.  We own extensive and contiguous land positions in the core areas of two of the premier North American shale plays. We believe our approximately 329,000 net acres in the southwestern core of the Marcellus Shale and our 102,000 net acres in the Utica Shale are characterized by consistent and predictable geology. However, 92% of this acreage is currently undeveloped or does not include wells that have been drilled or completed to a point of producing commercially viable quantities. Approximately 52% of our Marcellus acreage and 20% of our Utica acreage was held by production at June 30, 2013, while an additional 27% and 78%, respectively, does not expire for five years or more. However, 48% and 80% of our natural gas leases related to our Marcellus and Utica acreage, respectively, require us to drill wells that are commercially productive by the end of the primary term, and if we are unsuccessful in drilling such wells, we could lose our rights under such leases. As of June 30, 2013, all of our total aggregate proved, probable and possible reserves were attributable to properties that we operate.

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Multi-year, low-risk drilling inventory.  Our drilling inventory at June 30, 2013 consisted of 4,576 identified potential horizontal well locations on our existing leasehold acreage. We believe that we and other operators in the area have substantially delineated and de-risked our large contiguous acreage position in the southwestern core of the Marcellus Shale. We have drilled and completed 199 wells on our Marcellus Shale acreage with a success rate of 100%. We have drilled and completed 11 horizontal wells in the core of the Utica Shale with a 100% success rate.



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Exposure to large resource of liquids-rich gas and condensate.  Approximately 64% of our 4,576 identified potential horizontal well locations as of June 30, 2013 target the liquids-rich gas regions of the Marcellus and Utica Shales. The gas content of this liquids-rich gas allows for NGL processing that, coupled with the condensate, can significantly improve well economics. This exposure to a range of liquids contents allows us to optimize our drilling economics across a portfolio of liquids-rich gas locations in order to take advantage of the existing commodity price environment.



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Low-cost leader.  We are a low-cost leader in the U.S. Our ability to drill consistently long laterals, averaging over 7,000 lateral feet, helps us to reduce costs on a per-lateral-foot basis, which is a key competitive advantage. The contiguous nature of our leasehold and the lack of geologic complexity are critical to our ability to drill long laterals. Additionally, since June 2013, we have shortened our average frac stage lengths on many of our Marcellus Shale wells from 350 feet per stage historically to 150 to 250 feet per stage. Initial well results have shown increases in 24-hour initial production rates of 25% to 35% when compared to similar wells within the same geographic area. In addition, we estimate that the incremental costs attributable to the short stage lengths has averaged an estimated $1.5 million to $2.0 million per well. We have implemented operational efficiencies to continue lowering our costs, such as (i) pad drilling, (ii) development of an extensive water pipeline system, (iii) the use of less expensive, shallow vertical drilling rigs to drill to the kick-off point of the horizontal wellbore, (iv) the use of natural gas powered rigs and (v) our proactive approach to meeting our gathering, processing and compression infrastructure needs.



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Access to committed processing, compression and takeaway capacity in the Marcellus and Utica Shales. We have contracted a total of 750 MMcf/d of processing capacity in the Marcellus Shale, 400 MMcf/d of which is currently in service. Similarly, we have 300 MMcf/d of contracted processing capacity in the Utica Shale, with the option to access additional capacity. We also have secured 1,300,000 MMBtu/d of long-haul firm transportation capacity or firm sales and have committed to 20,000 Bbl/d of ethane takeaway capacity. We believe our commitment to midstream infrastructure allows us to commercialize our production more quickly at optimal prices, making us a logical consolidator of additional acreage in our core areas.



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Financial strength and flexibility.  As of June 30, 2013, after giving effect to this offering and the application of the net proceeds therefrom, we expect to have approximately $1.72 billion of available borrowing capacity under our credit facility (after deducting $32 million outstanding letters of credit). After the completion of this offering and the recent increase in lender commitments under our credit facility, together with our operating cash flow and hedging program, we believe we will have the financial flexibility to pursue our currently planned 2013 and 2014 development and delineation drilling activities.



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Proven and incentivized executive and technical teams.  We believe our management team's experience and expertise across multiple resource plays provides a distinct competitive advantage. Our officers have an average of over 30 years of industry experience in the Rocky Mountain, Midcontinent and Appalachian operating regions and have successfully built, grown and sold two unconventional resource-focused upstream companies and one midstream company in the past 15 years. Additionally, our technical team has drilled over 450 horizontal wells in the

Barnett, Woodford, Marcellus and Utica Shales over the past ten years. Our management team has a significant economic interest in us through their interest in our controlling stockholder, Antero Resources Investment LLC, or Antero Investment. Management's percentage interest in our stock held by Antero Investment may increase over time, without diluting public investors, if our stock price appreciates following this offering. We believe our management team's ability to increase their economic interest in us provides significant incentives to grow our stock price for the benefit of all stockholders.

Business Strategy

        Our strategy consists of the following principal elements:

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Create shareholder value through the development of our extensive drilling inventory.  Since initiating our drilling program with one rig in 2009, we have invested over $3.2 billion in land and drilling in the Appalachian Basin and currently intend to use an average of 17 rigs in 2013. With 15 rigs running in the Marcellus Shale, we are currently the most active driller in the area based on information from RigData. We intend to dedicate substantially all of our $1.45 billion drilling and completion budget in 2013 to develop our liquids-rich areas. Approximately 85% of the 2013 drilling and completion budget is allocated to the Marcellus Shale, and the remaining 15% is allocated to the Utica Shale.



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Enhance returns through a focus on optimizing full cycle economics.  We continually monitor and adjust our drilling program with the objective of achieving the highest total returns on our portfolio of drilling opportunities. We believe that we will achieve this objective by (i) minimizing the capital costs of drilling and completing horizontal wells, (ii) maximizing well production and recoveries by optimizing lateral length, the number of frac stages, perforation intervals and the type of fracture stimulation employed, (iii) targeting specific BTU windows within our leasehold position to optimize our hydrocarbon mix based on the existing commodity price environment, (iv) minimizing operating costs through efficient well management, and (v) pursuing infrastructure initiatives, such as the development of our extensive water pipeline system and gas gathering system.



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Maximize wellhead economics by ensuring timely development of processing and pipeline takeaway capacity and the marketing of our NGLs. We expect to continue to meaningfully increase our liquids production from the NGLs, oil and condensate associated with our growing natural gas production. We endeavor to ensure that we have sufficient processing capacity in place to recover NGLs when economically desirable. We have also secured long-term firm takeaway capacity and firm sales on major pipelines that are in existence or currently under construction in our core operating areas to accommodate our growing production and to manage basis differentials. Further, we plan to maximize the value of our NGLs through processing and marketing agreements with transporters and NGL end users.



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Continue growing our core acreage position through leasing and strategic acquisitions.  We intend to continue identifying and acquiring additional acreage and producing assets in our core areas in the Marcellus and Utica Shales. We believe that by managing a large team of dedicated landmen, we have a competitive advantage that enables us to continue to opportunistically add acreage to our core positions. This team of landmen has allowed us to build a large, contiguous acreage position in our Marcellus and Utica Shale plays, making us the logical acreage consolidator in our core areas. We initially targeted and acquired 114,000 net acres in the Marcellus Shale in 2008, based on specific geologic and technical analysis, and have selectively built our position to approximately 329,000 net acres. We started building our targeted Utica Shale acreage position in the fourth quarter of 2011 and currently have approximately 102,000 net acres of leasehold in the core of the liquids-rich window in Ohio.

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Manage commodity price exposure through an active hedging program to protect our expected future cash flows. We expect to continue to maintain an active hedging program designed to mitigate volatility in commodity prices and regional basis differentials and to protect our expected future cash flows. As of June 30, 2013, we had entered into hedging contracts through December 31, 2018 covering a total of approximately 943 Bcfe of our projected natural gas and oil production at a weighted average price of $4.80 per Mcfe. These hedging contracts include hedges for the six-month period ending December 31, 2013 covering a total of approximately 84 Bcfe of our projected natural gas and oil production at a weighted average price of $4.68 per Mcfe. This hedging program has led to over $650 million in realized gains over the past five years.

Risk Factors

        An investment in our common stock involves a number of risks. You should carefully consider, in addition to the other information contained in this prospectus, the risks described in "Risk Factors" before investing in our common stock. These risks could materially affect our business, financial condition and results of operations, and cause the trading price of our common stock to decline. You could lose part or all of your investment. You should bear in mind, in reviewing this prospectus, that past experience is no indication of future performance. You should read the section titled "Cautionary Statement Regarding Forward-Looking Statements" for a discussion of what types of statements are forward-looking statements, as well as the significance of such statements in the context of this prospectus.

Corporate Reorganization

        Antero Resources LLC was formed in October 2009 by members of our management team and the Sponsors, as defined below. Antero Resources Appalachian Corporation, a wholly owned subsidiary of Antero Resources LLC, was formed in March 2008 and renamed Antero Resources Corporation in June 2013. Pursuant to the terms of a corporate reorganization, which will be completed immediately prior to or contemporaneously with the closing of this offering, (i) all of the outstanding interests of our existing owners in Antero Resources LLC will be exchanged for similar interests in Antero Resources Investment LLC, or Antero Investment, and (ii) Antero Resources LLC will be merged into Antero Resources Corporation.

        In addition, we intend to transfer our midstream business to Antero Resources Midstream LLC, or Antero Midstream, following the closing of this offering. We will initially own all of the membership interests in Antero Midstream other than a special membership interest, which will be indirectly owned by Antero Investment. The special membership interest in Antero Midstream will provide Antero Investment with certain rights, including the right to cause an initial public offering of Antero Midstream as a MLP or similar structure. Following any such initial public offering, the special membership interest will convert into a general partner interest in the MLP, which will allow Antero Investment to manage Antero Midstream's business and affairs. Following any such initial public offering, Antero Investment will also hold incentive distribution rights in the MLP, which will represent the right to receive an increasing percentage of the MLP's quarterly cash distributions in excess of specified target distribution levels. See "Certain Relationships and Related Party Transactions—Antero Midstream" and "Corporate Reorganization."

        The following diagram indicates our ownership structure after giving effect to our corporate reorganization and assuming no exercise of the underwriters' options to purchase additional shares. See "Corporate Reorganization" for more information regarding our corporate reorganization.

(1)

Includes each of our Sponsors and certain members of our management team who have made investments in Antero Investment in exchange for investment units. For information on the entities and individuals who may be deemed to control the Sponsors and for a list of our management team (all of whom hold interests in Antero Investment), see "Principal and Selling Stockholders."

(2)

Holds profits interests in Antero Investment on behalf of members of our management team and other employees. All of the membership interests in Antero Resources Employee Holdings LLC are held by our employees. The compensation committee of Antero Investment has voting and control rights over the shares held by Antero Resources Employee Holdings LLC.

(3)

Represents an interest that provides Antero Investment with certain rights, including the right to cause an initial public offering of Antero Midstream as a MLP or similar structure. Following any such initial public offering, this special membership interest will convert into a general partner interest in the MLP, which will allow Antero Investment to manage Antero Midstream's business and affairs. Following any such initial public offering, Antero Investment will also hold incentive distribution rights in the MLP, which will represent the right to receive an increasing percentage of the MLP's quarterly cash distributions in excess of specified target distribution levels. See "Certain Relationships and Related Party Transactions—Antero Midstream."

Our Principal Stockholders

        Following the completion of this offering and our corporate reorganization, Antero Investment will directly own 88.2% of our common stock, or 86.5% if the underwriters' options to purchase additional shares from us and Antero Investment are exercised in full. Antero Investment is primarily owned by investment funds affiliated with or managed by Warburg Pincus LLC, Yorktown Partners LLC and Trilantic Capital Partners, or collectively, the Sponsors, and certain members of our management. See "Principal and Selling Stockholders" and "Corporate Reorganization—Limited Liability Company Agreement of Antero Investment."

        Warburg Pincus LLC is a leading global private equity firm focused on growth investing. The firm has more than $40 billion in assets under management. Its active portfolio of more than 125 companies is highly diversified by stage, sector and geography. Warburg Pincus is an experienced partner to management teams seeking to build durable companies with sustainable value. Founded in 1966, Warburg Pincus has raised 13 private equity funds which have invested more than $45 billion in over 675 companies in more than 35 countries. Since the late 1980s, Warburg Pincus has invested more than $6 billion in energy and natural resources companies around the world. In addition to Antero Resources LLC, notable energy investments for which the firm was lead and/or founding investor include Bill Barrett Corporation (NYSE: BBG), Encore Acquisition Company (NYSE: EAC, since acquired by Denbury Resources), Kosmos Energy Ltd. (NYSE: KOS), Laredo Petroleum Holdings, Inc. (NYSE: LPI), MEG Energy (TSX: MEG), Newfield Exploration (NYSE: NFX), Spinnaker Exploration (NYSE: SKE, since acquired by Norsk Hydro/Statoil) and Targa Resources (NYSE: NGLS, TRGP). The firm is headquartered in New York with offices in Amsterdam, Beijing, Frankfurt, Hong Kong, London, Luxembourg, Mumbai, Port Louis, San Francisco, Sao Paulo and Shanghai.

        Yorktown Partners LLC is a private investment manager investing exclusively in the energy industry with an emphasis on North American oil and gas production, and midstream businesses. Yorktown has raised 10 private equity funds totaling over $6.5 billion. Yorktown's investors include university endowments, foundations, families, insurance companies, and other institutional investors. The firm is headquartered in New York.

        Trilantic Capital Partners is a global private equity firm focused on control and significant minority investments in North America and Europe with primary investment focus in the business services, consumer, energy and financial sectors. The firm currently manages four institutional private equity funds with aggregate capital commitments of $5.7 billion. Trilantic has offices in New York, London, Guernsey and Luxembourg.

Emerging Growth Company Status

        We are an "emerging growth company" as defined in the Jumpstart Our Business Startups Act, or the JOBS Act. For as long as we are an emerging growth company, unlike other public companies, we will not be required to:

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provide an auditor's attestation report on management's assessment of the effectiveness of our system of internal control over financial reporting pursuant to Section 404(b) of the Sarbanes-Oxley Act of 2002;



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comply with any new requirements adopted by the Public Company Accounting Oversight Board, or the PCAOB, requiring mandatory audit firm rotation or a supplement to the auditor's report in which the auditor would be required to provide additional information about the audit and the financial statements of the issuer;



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comply with any new audit rules adopted by the PCAOB after April 5, 2012, unless the Securities and Exchange Commission, or the SEC, determines otherwise;

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provide certain disclosure regarding executive compensation required of larger public companies; or



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obtain shareholder approval of any golden parachute payments not previously approved.

        We will cease to be an "emerging growth company" upon the earliest of:

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the last day of the fiscal year in which we have $1.0 billion or more in annual revenues;



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the date on which we become a large accelerated filer;



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the date on which we issue more than $1.0 billion of non-convertible debt over a three-year period; or



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the last day of the fiscal year following the fifth anniversary of our initial public offering.

        In addition, Section 107 of the JOBS Act provides that an emerging growth company can take advantage of the extended transition period provided in Section 7(a)(2)(B) of the Securities Act for complying with new or revised accounting standards, but we intend to irrevocably opt out of the extended transition period.

Corporate Information

        Our principal executive offices are located at 1625 17th Street, Denver, Colorado 80202, and our telephone number at that address is (303) 357-7310. Our website is located at www.anteroresources.com. We expect to make our periodic reports and other information filed with or furnished to the SEC available free of charge through our website as soon as reasonably practicable after those reports and other information are electronically filed with or furnished to the SEC. Information on our website or any other website is not incorporated by reference herein and does not constitute a part of this prospectus.

The Offering

        The information above excludes 16,534,375 shares of common stock reserved for issuance under our 2013 Long-Term Incentive Plan, or the LTIP, that we intend to adopt in connection with the completion of this offering.

Summary Historical Consolidated Financial Data

        The following table shows our summary historical consolidated financial data, for the periods and as of the dates indicated, for Antero Resources LLC and its subsidiaries.

        The summary statement of operations data for the years ended December 31, 2010, 2011 and 2012 and the balance sheet data as of December 31, 2011 and 2012 are derived from our audited consolidated financial statements included elsewhere in this prospectus. The balance sheet data as of December 31, 2010 is derived from our audited consolidated financial statements not included in this prospectus. The summary statement of operations data for the three and six months ended June 30, 2012 and 2013 and the balance sheet data as of June 30, 2013 are derived from our unaudited consolidated financial statements included elsewhere in this prospectus. The balance sheet data as of June 30, 2012 is derived from our unaudited consolidated financial statements not included in this prospectus.

        The statement of operations data for all periods presented has been recast to present the results of operations from our Piceance Basin and Arkoma Basin operations in discontinued operations. The losses on the sales of these properties are also included in discontinued operations in 2012. The results from continuing operations reflect our remaining operations in the Appalachian Basin. No part of our general and administrative expenses or interest expense was allocated to discontinued operations.

        The summary historical consolidated financial data has been prepared on a consistent basis with our audited consolidated financial statements. In the opinion of management, such summary historical consolidated financial data reflects all adjustments (consisting of normal and recurring accruals) considered necessary to present our financial position for the periods presented.

        The results of operations for the interim periods are not necessarily indicative of the results that may be expected for the full year because of the impact of fluctuations in prices received from natural gas and oil, natural production declines, the uncertainty of exploration and development drilling results and other factors. The summary financial data presented below are qualified in their entirety by reference to, and should be read in conjunction with, "Capitalization," "Management's Discussion and

Analysis of Financial Condition and Results of Operations" and our consolidated financial statements and related notes included elsewhere herein.

Summary Reserve, Production and Operating Data

Summary Reserve Data

        The following table summarizes our estimated proved reserves and related standardized measure and PV-10 at December 31, 2010, 2011 and 2012 and June 30, 2013 based on SEC pricing (and not giving effect to any pricing sensitivities). See "Business—Our Operations—Reserve Data" for an illustration of the sensitivity of our estimated reserves and related PV-10 to changes in product price levels.

        Our estimated proved reserves and PV-10 as of December 31, 2012 and June 30, 2013 are based on evaluations prepared by our internal reserve engineers, which have been audited by our independent reserve engineers, DeGolyer and MacNaughton, or D&M. Our estimated proved reserves as of December 31, 2011 were based on evaluations prepared by our internal reserve engineers, which were audited by D&M and Ryder Scott & Company, or Ryder Scott. Over 99% and 85% of our estimated proved, probable and possible reserves as of June 30, 2013 and December 31, 2012, respectively, were audited by D&M. Over 85% of our estimated proved reserves as of December 31, 2011 were audited by D&M or Ryder Scott. Over 99% of our estimated proved reserves as of December 31, 2010 were prepared by D&M or Ryder Scott. For each period presented, the specific percentage of our estimated reserves audited or prepared (as applicable) by D&M or Ryder Scott, which we collectively refer to as our independent reserve engineers, is disclosed in the summary report of D&M or Ryder Scott incorporated by reference into, or filed as an exhibit to, the registration statement of which this prospectus forms a part. See "Business—Our Operations—Reserve Data—Preparation of Reserve Estimates" for definitions of proved, probable and possible reserves and the technologies and economic data used in their estimation. See "—Our Properties—Reserves."

        Our estimated proved reserves at December 31, 2010 and 2011 included reserves attributable to our Arkoma Basin and Piceance Basin assets that were sold during 2012. The information in the following table does not give any effect to or reflect our commodity hedges. In addition, the estimated proved reserves below assume ethane recovery as of December 31, 2010, 2011 and 2012 and ethane rejection as of June 30, 2013 on our liquids-rich natural gas. See "Business—Our Operations—Reserve Data" for more information about our reserves and pricing sensitivities.