Mr. Tooley specializes in business, real property, natural resources and commercial litigation, including arbitrations, trials and appeals.  Since 1988, Mr. Tooley has litigated and arbitrated a wide range of contract and business disputes, including disputes involving real property transactions, development and joint venture agreements, land use, corporate and partnership matters, mineral rights, anti-trust claims, class actions, governmental regulation and agency action, torts, construction claims, oil and gas operations, mining, employment, insurance coverage, and a variety of other torts and business disputes.

Representative Matters

Joint Ventures, Development Agreements & Business Torts

  • Riviera Drilling & Exploration Co. v. Gunnison Energy Corp., et al., 412 Fed.Appx. 89 (C.A.10 2011) (exploration corporation’s antitrust action dismissed against energy companies).
  • Gunnison Energy Corporation v. SG Interests I, Ltd., District Court, Gunnison County, Colorado, Case No. 2011CV262 (dispute over area of mutual interest agreement and operatorship of an $80 million natural gas pipeline).
  • Mountain Petroleum Corporation et al. v. Foundation Energy Management, LLC, Case No. 2015CV030304, Denver District Court (2015) (Defended claim seeking over 8 million in damages for alleged tortious interference with prospective purchase and sale agreement and dispute over attempted sale of the right of operatorship of 285 natural gas wells in Yuma County, Colorado).
  • Enerplus Resources (USA) Corp. v. Slawson Exploration Company, Inc., (AAA 2006) (obtained arbitration award on behalf of defendant on all claims concerning interpretation of area of mutual interest agreement covering Bakken play in Montana).
  • Edwards Energy Corp. v. Texaco Exploration and Production, Inc., U.S. Dist. Colo., Case No. 02-MK-0893 (2002) (dispute over joint venture agreement, title, accounting and back-in working interests).
  • San Juan Basin Consortium, Ltd v. EnerVest San Juan Acquisition Ltd., 67 F.Supp.2d 1213 (D. Colo. 1999) (successfully defended claims re: back-in reversionary interest at payout involving Section 29 tax credits).
  • Encana Oil & Gas (USA), Inc. v. QEP Energy Company and True Oil LLC, Sweetwater County District Court, Wyoming.  Case C-10-505-R. (breach of contract action relating to right to convert overriding royalty interest to working interest at payout).


  • Golden Eagle Exploration, LLC v. Weatherford U.S., L.P., Case No. 0707-119, Grand County, Utah (2007) (multi-million dollar claims arising out of failute to properly hang liner, leading to cementation of drill pipe and four months of milling and fishing operations).
  • Rippy v. SG Interests I, Ltd., District Court, Mesa County, Colorado, Case No. 2010CV4164 (defense of action brought by Mesa County rancher alleging trespass and breach of natural gas pipeline easement agreement; obtained jury verdict in favor of defendant on all claims and an award of $986,262 for damages and recovery of attorney fees and costs on defendant's counterclaims for interference with pipeline construction operations).
  • Petrogulf Corporation v. Northern Production Co. Inc., Case No. 03CV1762, Denver District Court, (2003) (claims against drilling contractor for dropping over 4,000 feet of tubing which caused it to cork screw and destroy the well).
  • J.W. Gibson v. Murfin Drilling Co., Case No. 98 S 2183, Denver District Court (1998) (claims against drilling contractor for negligence and breach of contract involving lost mud circulation and stuck drill string).
  • DIA construction claims. Represented various clients on bid protests, payment claims and contract disputes in connection with the construction of Denver International Airport.
  • Reef USA Fund III v. Macerich Management Co., Denver District Court. (Represented manager of shopping mall in multiple claims involving disturbance of asbestos during renovation of the shopping mall).
  • Scott Company of California v. M.K. Ferguson, 832 P.3d 1000 (Colo. 1991) (jury verdict for subcontract on delay impacts and overruns for work in constructing the Anheuser-Busch Brewery in Fort Collins).

Oil and Gas Leases

  • Rock Creek Ranch, Ltd. v. Riviera Drilling and Exploration, Co., 2010 WL 3036515 (Colo. App. 2010) (obtained judgment for landowner terminating oil and gas lease for failure to timely develop and an award of attorney’s fees, affirmed on appeal).
  • CC Karval Cattle Company, L.P. v. Fossil Creek Resources, L.L.C., Lincoln County District Court, Case No. 2013CV20. (successfully defended oil and gas lessee in actions seeking declaration of lease termination).
  • Bolton v. Renegade Oil & Gas Company, LLC, Kiowa County District Court, Case No. 2013CV30003. (successfully defended claim seeking to terminate oil and gas lease for failure to produce in paying quantities).
  • United Dairy Farmers, Inc. v. BP American Production Company, U.S. District Court, Civil Action No. 06CV2536, U.S. Dist. Colo. (2006) (claim against lessee for breach of implied covenant to protect against drainage).

Government Agencies and Regulations

  • Western Energy Alliance v. Salazar, 2011 WL 3737520 (D. Wyo. 2011) (judgment requiring Secretary of Interior to make lease issuance decisions within 60 day period mandated by Congress under the Mineral Leasing Act).
  • SG Interests v. Board of County Commr's of Gunnison County, Colorado (Gunnison County District Court, 2011) (challenge to legality of county oil and gas regulations and preemption of local regulations after COGCC's overhaul of state oil and gas regulations).
  • In re: BP America Production Company for Involuntary Pooling, Oil and Gas Conservation Commission of the State of Colorado, Cause No. 112, Docket No. 1010-U-57. (successfully opposed application seeking retroactive force pooling for wells governed by communitization agreement with the Southern Ute Indian Tribe).

Royalty Disputes

  • Mountain West Exploration, Inc. et. al. v. Evergreen Resources, Inc., Case No. 02CV8854, Denver District Court (2002) (Defense of multi-million dollar class action lawsuit for alleged underpaid royalties, successfully settled during class certification proceedings).
  • Rogers v. Westerman Farm Co, 986 P.2d 967 (Colo. App. 1998), rev’d and remanded 29 P.3d 887 (Colo. 2001) (defended royalty underpayment claims involving 223 natural gas wells in Yuma County, Colorado. After favorable jury verdict and court of appeals decision, favorably settled after Colorado Supreme Court remanded for new trial).
  • Encana Oil & Gas (USA) Inc. v. Sally Miler et al., Denver District Court, Case No. 2016CV031444. (suit challenging whether class action royalty settlement agreement authorizes subsequent class wide arbitration).
  • Federal, State and Indian Royalty Audits. Represented numerous clients in defending royalty audits by ONRR/MMS, State of Colorado and Indian Tribes.

Title, Trespass, Surface Use

  • Schares v. Renegade Oil & Gas Co., L.L.C., 2008 WL 4292664 (Colo. App. 2008), cert denied, 2009 WL 1041496 (Colo. 2009) (obtained dismissal of surface owner trespass claim and an award of attorneys fees against surface owner, affirmed on appeal).
  • Comet Energy Services, LLC v. Powder River Oil & Gas Ventures, LLC, 239 P.3d 382 (Wyo. 2010) (cleared title to oil and gas leasehold interests purchased at auction).
  • Newton v. Morrison, 2009 WL 1555447 (Colo. App. 2009) (successful trial judgment after remand establishing ownership of disputed minerals).
  • Steiner v. Pioneer Natural Resources (USA) Inc., Case No. 03CV143 (Las Animas County District Court, 2003) (obtained injunction against surface owners enjoining them from interfering with access, surface use and operations).
  • Petrogulf Corp. v. Arco Oil & Gas Co., 92 F. Supp. 2d 111 (D. Colo. 2000) (mineral trespass dispute over the location and drainage of gas well drilled on fee lands within Southern Ute Indian Reservation).


  • DynaResources de Mexico, S.A. de C.V. et al. v. Goldgroup Resources, Inc., U.S. District Court, Civil Action No. 14-cv-01527, and International Centre for Dispute Resolution, ICDR 50 501 T 00226 14. Represented Mexican gold mining company in dispute over ownership and control of gold mine under an Earn/In Agreement, applicable Mexican law, and challenge to the scope of claims subject to arbitration under the Panama Convention.
  • Utah Energy Corp. v. Lammert, Civil No. 0807-59, San Juan County, Utah (2009) (title and partnership dispute over uranium mining claims near Moab, Utah).
  • Bar Nothing Ranch, L.L.C. v. Febraro Construction Company, Las Animas County, Colo. (Claim by owner over gravel pit operations, accounting and termination of gravel pit lease).
  • Western Hog Ranch v. Western Mining Corporation, (D. Nev. 1999) (dispute over reclamation of gold mine in Nevada).
  • Represented numerous clients concerning validity and disputes over mining claims and mining operations.


  • Wimmer v. City of Aurora, Civil Action No. 96-N-1547 (D. Colo. 2006) (jury verdict against City of Aurora, Aurora Chief of Police, individually, and Aurora Deputy Chief of Police, individually, under American with Disabilities Act and outrageous conduct claims).
  • Eric Knight v. Excell Energy, LLC, Case No. 1:15-cv-02456, U.S. District Court for the District of Colorado. (successfully defended oil and gas company in class action alleging violation of the Worker Adjustment and Retraining Notification Act of 1988 in connection with alleged mass layoff of oilfield workers).
  • Represented numerous employers and employees in disputes over wages, ownership interests, non-compete agreements, misappropriation of trade secrets, and discrimination and wrongful termination claims.

Publications, Presentations & Accolades

  • Top Lawyers, Civil Litigation, 5280 - The Denver Magazine, 2017
  • Board of Directors, Denver Mountain Parks Foundation, 2016
  • Selected to Colorado Super Lawyers, 2009-2019
  • Selected for Inclusion in The Best Lawyers in America© in the fields of Natural Resources Law, 2013-2020 and Commercial Litigation, 2015-2020
  • Co-author of "The Marketable Product Approach in the Natural Gas Royalty Case," 44 Rocky Mt. Min. L. Inst. 21-1 (1998)
  • Adjunct Professor of Oil and Gas Law at the University of Denver Law School (1998)
  • Av rated by Martindale Hubbell
  • Phi Beta Kappa Society
  • Frequent Lecturer, various continuing legal education seminars, professional associations, and University of Denver School of Law


Mr. Tooley was born March 14, 1962. He is married with two children and has been a member of the Dale Tooley Cancer Research Laboratory since 1995.

Brian S. Tooley

Practice AREAS
  • Commercial and Civil Litigation
  • Trials and Appeals
  • Arbitration
  • Business Contracts & Torts
  • Real Property Litigation
  • Oil and Gas
  • Natural Resources
  • Construction
  • Employment

  • J.D., University of Colorado at Boulder, Order of the Coif, 1988
  • B.A., University of Colorado at Boulder, with distinction, 1984

Bar Admissions / Qualifications
  • Colorado, 1988
  • U.S. District Court, District of Colorado
  • U.S. Court of Appeals, Tenth Circuit
  • U.S. Court of Federal Claims
  • South Ute Indian Tribal Court through 2015

Professional & Community Activities
  • American Bar Association
  • Colorado Bar Association
  • Denver Bar Association
  • Member, Environmental and Natural Resources section, Colordo Bar Association
  • Board Member, Independent Petroleum Association of Mountain States, 2001-2007
  • Secretary, Independent Petroleum Association of Mountain States, 2001-2005
  • Member, Legal, Legislation and Regulatory Committee, Colorado Oil and Gas Association, 2015
  • Board Member, Denver Mountain Parks Foundation, 2016