Thomas Sansonetti

Partner

555 17th Street, Suite 3200

Denver, CO 80202

505 9th St. NW, Suite 700

Washington, DC 20004

2020 Carey Avenue, Suite 800

Cheyenne, WY 82001

T: 307.778.4250

A longtime litigator and project team leader, Tom helps clients permit and develop projects with potential obstacles in mind.

Long before a lawsuit can threaten a project, he counsels clients on how to develop effective plans of action that will meet government environmental permitting requirements and stand up to judicial scrutiny when those clients' projects are challenged in court.

Tom joined Holland & Hart in 1993 and built a nationally recognized practice in natural resources and environmental law. Considered an expert in natural resources and environmental matters, Tom served as an Assistant Attorney General for the Environment and Natural Resources Division in the Department of Justice and as the Solicitor and Associate Solicitor for Energy and Resources at the Department of the Interior. He has argued before the U.S. Supreme Court and in seven Federal Circuit Courts of Appeal, and served as a federal prosecutor in environmental crimes cases. Tom’s appellate experience highlights his ability to argue cases at all levels of the federal court system.

Active in politics, Tom was Chairman of the Republican Party in Wyoming from 1983-1987. He also served as Wyoming's Republican National Committeeman (1996-2001) and as General Counsel for the Republican National Committee (2001). Tom served as the Chief of Staff and Legislative Director for Wyoming Congressman Craig Thomas during the 101st Congress.

Client Results

Energy and Natural Resources Projects

Team leader for permitting natural gas pipeline through four states and 680 miles.
Represented a regional natural gas pipeline operator in negotiations with tribes to purchase a major natural gas pipeline.
Represented various companies in obtaining rights-of way over state, federal, and tribal lands.
Represented an international geothermal company in their negotiations to place a project on an American Indian reservation.
Represented a company in the negotiation with an American Indian tribe for the construction of a natural gas plant on an American Indian reservation.
Represented a major national resource company in obtaining the permit to construct a dam and hydropower facility.
Represented a public utility in the negotiations with an American Indian tribe to explore for coal on the Indian reservation.

Environmental Litigation

Defended the state and federal permits granted to a major U.S. natural gas company for the construction of a natural gas pipeline in the 9th Circuit Court of Appeals.
Represented a major U.S. natural gas pipeline operation in suing the federal government over the clean-up of uranium tailings on an American Indian reservation.
Represented a major U.S. natural gas pipeline operation in defending a class action lawsuit brought by individual tribal members claiming the amount of right-of-way lease payments were deficient.
Part of a litigation team that successfully represented Pennsylvania Power and Light before the United States Supreme Court in overturning a Montana Supreme Court decision concerning the ownership of riverbeds within the state.
Represented a public utility in negotiations with an American Indian tribe to explore for coal on the tribe’s reservation.

Representation of Clients before Federal and State Agencies and Congress

Represented a regional public utility before the EPA on issues relating to the Clean Air Act.
Represented trona and coal companies on regulatory matters before the Department of the Interior.
Represented various entities in dealing with the intricacies of the Indian Regulatory Gaming Act and the Bureau of Indian Affairs.
Represented both companies and ranchers on clarifying their water rights in western states.
Represented a large charitable trust health group in obtaining funding to improve and increase FDA inspections for imported foods.

Experience

Experience in many areas of energy and natural resources law, including:

American Indian law
Appeals of adverse federal agency decisions before the Interior Board of Land Appeals and Interior Board of Indian Appeals
Clean Air Act and Clean Water Act issues
Development of renewable energy projects, including geothermal, solar, and wind projects
Endangered Species Act
Oil and natural gas permitting
Permitting of oil and natural gas pipelines and electric transmission, including right-of-ways
Public lands management
Surface mining development and reclamation
Water rights

News

Publications

10/04/2021
The Western Mega-drought's Impacts on Practicing Water Law in the West American College of Environmental Lawyers (ACOEL)

Speaking Engagements and Events

October 2016
Looking Ahead to the Next Administration: Who Will Decide Policy on Energy, Environment & Legal Issues?
EnviroFest 2016 - "The Political Economy of the Environment"
April 2014
Representing Clients Before Federal Agencies
Washington and Lee University School of Law
July 2016
Looking Ahead to the Next Administration
Independent Petroleum Association of America Mid-Year Meeting
September 2016
Clinton, Bush, and Obama: A Panel Discussion with the Justice Department's Environmental Leaders for Three Presidents
2016-2017 University of Michigan Environmental Law and Policy Program Lecture Series, Panelist
October 2016
An Update on Energy/Natural Resource Issues of Interest
2016 University of Wyoming Landscape Discussion on Energy Law & Policy in the Rockies
January 14, 2015
The legal and policy aspects of renewables project development in California
Federalist Society event at Stanford Law School, Panelist

Professional and Civic Affiliations

Washington & Lee University School of Law, Member, Law Council, 2011-2019
University of Denver Sturm College of Law, Natural Resources Law, Practitioner in Residence, 2012
United States Commission on Civil Rights for the State of Wyoming, Chairman, 2008-2012
Republican National Committee, General Counsel, 2001
Wyoming's Republican National Committeeman, 1996-2001
Wyoming Republican Party, Chairman, 1983-1987

Recognition

Chambers USA, Native American Law, Senior Statesperson, Nationwide, 2012-2023
American College of Environmental Lawyers, Fellow, 2012-present
American Law Institute, Member 2002-present
Lawdragon, Green 500: Leaders in Environmental Law, 2023
Lawdragon, 500 Leading Environmental and Energy Lawyers, 2021
The Best Lawyers in America©, Environmental Law, Government Relations Practice, 2007-2023; Native American Law, 2016-2023; Oil and Gas Law, 2018-2023
Mountain States Super Lawyers®, Energy & Resources, 2011-2022
Mountain States Super Lawyers®, "Top 100 Lawyers," 2018
Denver Business Journal, Who’s Who in Energy, 2012-2013

Environmental Litigation Wildlife and Protected Species Water Resources Environmental Federal Lands Permitting Environmental Transactions

Energy and Resources Oil and Gas Mining Oil and Gas Litigation Oil and Gas Regulatory

Washington & Lee University
J.D., 1976

University of Virginia, Colgate Darden School
M.B.A., 1973

University of Virginia
B.A., 1971

Foreign Affairs, With Distinction

Colorado

District of Columbia

Wyoming

U.S. Supreme Court

U.S. Circuit Courts of Appeals for the D.C., Federal, First, Second, Eighth, Ninth, and Tenth Circuits

Practice Areas

Industries

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