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Anthony Shaheen


555 17th Street, Suite 3200, Denver, CO 80202

Tony Shaheen’s courtroom experience and industry knowledge give his natural resources clients a huge advantage in resolving disputes.

His practice emphasizes natural resources litigation.  But his clients (oil and gas companies and pipeline companies) call on him to represent them in a wide variety of cases, from breach of contract, to class action royalty cases, to alleged antitrust violations, to personal injury and wrongful death, and to product liability. Tony has litigated and tried some of the most important oil and gas cases in the Rocky Mountain Region.  His achievements include obtaining verdicts and decisions for his clients that have permanently altered oil and gas law in Colorado and Wyoming.

Tony has also defended and tried criminal cases, ranging from a criminal action brought for violation of the Resource Conservation and Recovery Act to first-degree murder.

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  • Environmental & Natural Resources Litigation
  • Civil and criminal multiparty litigation
  • Breach of contract
  • Royalty
  • Operational Disputes
  • General Commercial Litigation for the Energy & Resources Industry
  • Environmental Contamination
  • Products liability
  • Personal Injury


  • Handled appeals in Colorado state courts, Wyoming Supreme Court and in the Eighth and Tenth Circuit Courts of Appeals, covering areas as diverse as convincing the Wyoming Supreme Court to adopt laches as a defense to breach of contract where the statute of limitations has not run to a criminal habeas petition in front of the Tenth Circuit.

Client Results

  • In a case of first impression in Wyoming, obtained defense verdict for major oil and gas company for alleged breach of joint operating agreement by prevailing on the defense of laches. The verdict was affirmed by the Wyoming Supreme Court which held that laches was an available defense to a breach of contract claim and that the defense had been proven.

  • Tried and obtained the first, and to date, only defense verdict in a case brought under Rogers v. Westerman Farm Co., a landmark Colorado Supreme Court decision which dramatically changed Colorado oil and gas law. The class of 2500 royalty owners claimed the producer had underpaid royalties because the gas was not in marketable condition until after it had been processed into residue gas and natural gas liquids. The jury disagreed, concluding that the royalty owners had been paid properly. 

  • Lead trial counsel for 100 named oil company defendants and a defendant class of 3,000 royalty owners involving ownership of the coalbed methane underlying the Southern Ute Indian Reservation. The United States Supreme Court affirmed judgment in favor of the companies and the class in 1999.

  • Obtained acquittal in criminal environmental trial for violation of the Resource Conservation and Recovery Act.

  • Successfully sued the Ute Indian Tribe of the Uintah and Ouray Reservation, Utah, in Denver District Court, defeating claim of sovereign immunity.

  • Obtained defense verdict for refinery on antitrust claim that it engaged in price discrimination in violation of the Robinson-Patman Act.

  • Obtained the successful construction and completion of two pipelines across the Ft. Berthold Indian Reservation during the DAPL protests, obtaining a preliminary injunction in USDC (North Dakota) and defeating two appeals by the Tribe to the Eighth Circuit Court of Appeals.


Bar Admissions


  • The Best Lawyers in America© Energy Law; Natural Resources Law, 1999-2022
  • Colorado Super Lawyers® Energy and Natural Resources, 2010-2016

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