Ron Tenpas > Vinson & Elkins LLP > Washington DC, > Lawyer Profile

Vinson & Elkins LLP
WASHINGTON, DC 20037-1701

Work Department

Environmental & Natural Resources


Ron Tenpas is one of the country’s preeminent environmental litigators. A former Assistant Attorney General (AAG) for the Environment and Natural Resources Division of the U.S. Department of Justice, Ron represents clients in civil and criminal investigations related to alleged environmental violations, imports and other matters. He also represents companies and trade associations in commenting on proposed regulations and in litigation challenging new regulatory provisions.

In counseling clients, Ron draws upon 12 years of experience in the Justice Department. As AAG, a title he held from 2007 until 2009, he managed a 700-person division that included 400 lawyers. He oversaw civil and criminal litigation arising under more than 150 environmental and natural resources laws.

In addition, as AAG Ron defended the government when the government was sued in connection with its own use of natural resources. Ron also advised Cabinet and White House officials on policy and litigation risks associated with the environmental laws. Under Ron’s watch, the Justice Department secured what was at the time the largest criminal penalty under the Clean Air Act.

Before he was appointed AAG, Ron served as an Associate Deputy Attorney General, as the U.S. Attorney in the Southern District of Illinois, and as an Assistant U.S. Attorney in the District of Maryland and the Middle District of Florida. He investigated and tried white-collar matters related to healthcare fraud and public corruption.

A Rhodes Scholar and editor-in-chief of the Virginia Law Review, Ron served as a clerk to Chief Justice William H. Rehnquist of the U.S. Supreme Court.

Ron’s environmental practice has been recognized by Chambers USA. A source quoted by Chambers said Ron has “a unique combination of being a skilled environmental lawyer and being able to clearly communicate to his clients and develop a path forward” (2019).


  • University of Virginia School of Law, 1990, J.D.
  • University of Oxford, Balliol College, 1987, B.A.
  • Michigan State University, 1985, B.A., with high honors

Lawyer Rankings

United States > Environment > Environment: transactional

The environmental and natural resources group at Vinson & Elkins LLP acts for clients on high-value M&A, the buying and selling of assets, financings and project development, and is well versed in acquiring and defending permits pertaining to air, water and wetlands. The practice has a strong track record in handling the environmental aspects of energy transactions and is led by Ron Tenpas in Washington DC. Also in Houston, Matthew Dobbins is a name for regulatory counseling, remedial issues, environmental litigation, energy transition and transactional matters, with a focus on low-carbon ventures. Casey Hopkins in DC is experienced in securities offerings, private placements and environmental approvals. Larry Nettles has retired.