Tyler G. Welti

Welti Tyler

Tyler Welti focuses on environmental law, regulatory, and litigation matters, drawing on his experience with the U.S. Department of Justice's Environment and Natural Resources Division. Tyler handles a wide range of federal and state environmental, natural resources, land use, environmental justice, and litigation matters, including government enforcement actions, citizen suits, class actions, California Environmental Quality Act (CEQA) petitions, and Administrative Procedure Act challenges and appeals. He has particular experience in counseling and defending project developments involving a federal or state government, including transportation, energy, timber, mining, water, and other infrastructure projects.

Tyler's experience includes counseling and litigation involving the National Environmental Policy Act (NEPA), Endangered Species Act (ESA), Clean Water Act (CWA), Clean Air Act (CAA), Marine Mammal Protection Act (MMPA), Indian Gaming Regulatory Act (IGRA), National Historic Preservation Act (NHPA), Federal Land Policy and Management Act (FLPMA), National Forest Management Act (NFMA), Outer Continental Shelf Lands Act (OCSLA), Mining Law, Mineral Leasing Act, Antiquities Act, Migratory Bird Treaty Act, and many other state and federal laws and regulations.

Tyler began his career as a trial attorney in the U.S. Department of Justice, Environment & Natural Resources Division, where he served as lead counsel on numerous major environmental cases. He also served as a judicial law clerk for the U.S. Court of Appeals for the Ninth Circuit.



Government Experience

  • Trial Attorney, U.S. Department of Justice, Environment & Natural Resources Division

Representative Matters

  • Represented the federal government in a case challenging the reopening of a uranium mine on the rim of the Grand Canyon on NEPA and other grounds, due to alleged impacts on water and protected species. Defeated motions for preliminary injunctions, prevailed on a motion for summary judgment, and won on appeal, securing the leading case on NEPA supplementation in the Ninth Circuit. (Center for Biological Diversity v. Salazar, 791 F. Supp. 2d 687, D. Ariz. 2011; aff'd, 706 F.3d 1085, 9th Cir. 2013, challenging management of a uranium mine near the Grand Canyon)
  • Represented the federal government in three cases raising more than a dozen claims challenging an agency's management of the Upper Missouri River Breaks National Monument, including oil and gas, roads, and airstrips. Prevailed on all claims in all cases in district court, and won all substantial claims on appeal. (In re Mont. Wilderness Assoc., 807 F. Supp. 2d 990, D. Mont. 2011; aff'd in part, rev'd in part, 725 F.3d 988, 9th Cir. 2013)
  • Represented the federal government in a challenge to Secretary Salazar's first act in office, which reversed a controversial onshore oil and gas lease sale completed in the final days of the previous administration. Prevailed in district court and on appeal. (Impact Energy v. Salazar, 2010 WL 3489544, D. Utah Sept. 1, 2010; aff'd, 693 F.3d 1239, 10th Cir. 2012; cert. denied, 134 S. Ct. 67, 2013)
  • Represented the federal government in Alaska's challenge to moratoria on oil and gas drilling imposed in the wake of the Deepwater Horizon oil spill. Prevailed in expedited summary judgment proceedings. (Alaska v. Salazar, No. 10-cv-00205 at ECF No. 80, D. Alaska Jan. 26, 2011)
  • Represented the federal government in two cases raising more than $145 million in liability, challenging an agency decision that caused several offshore oil and gas leases to expire. Prevailed at the summary judgment stage and won on appeal. (Aera Energy v. Salazar, 691 F. Supp. 2d 25, D.D.C. 2010; Noble Energy, Inc. v. Salazar, 691 F. Supp. 2d 14, D.D.C. 2010; aff'd, 642 F.3d 212, D.C. Cir. 2011; cert. denied, 132 S. Ct. 252, 2011)
  • Representing the federal government, brokered a settlement agreement between the federal government, environmental groups, and industry in a challenge to seismic exploration of the Gulf of Mexico based on alleged impacts to protected species.
  • Representing a state Department of Transportation as part of a litigation team, prevailed in several challenges based on NEPA, the ESA, the Clean Water Act, and other statutes to a major highway project.
  • Represented a state Department of Transportation and prevailed on all claims in a challenge under NEPA, the Clean Air Act, the Clean Water Act, and other laws to a major bridge construction project.
  • Defended utility-scale solar energy developments on federal and state land.
  • Counseled private companies and local governments on licensing and environmental review of commercial space projects.




  • J.D. University of Virginia School of Law 2008
    • Notes editor, Virginia Law Review
  • B.A. English Yale University 2002

Bar Admissions

  • California
  • District of Columbia

Clerk Experience

  • Honorable Consuelo M. Callahan U.S. Court of Appeals for the Ninth Circuit

Professional Memberships and Activities

  • Chair, Public Land and Resources Committee of the American Bar Association's Section of Environment, Energy, and Resources 


  • Chambers USA, Environment, California, 2024
  • The Best Lawyers in America, Environmental Law, 2023 – 2024
  • U.S. Department of Justice, Special Distinction Award (Presented for tireless efforts on behalf of the American people regarding work on the Deepwater Horizon litigation)