John Masterson

Practice Areas

Commercial and Complex Litigation

Energy and Natural Resources Litigation

Tort and Civil Rights Defense

Energy Regulation and Permitting

Governmental Communications

Nonprofit and Corporate Law

Administrative, State, and Federal Appeals

Client Counseling and Dispute Resolution

Career

John Masterson’s practice includes litigation, government relations, transactional work, and strategic counsel for government, public and private corporations, nonprofits, and individuals. Mr. Masterson began his legal career with 16 years in criminal law, serving as a public defender, Assistant District Attorney, and Assistant U.S. Attorney. Over that time, he investigated and prosecuted matters ranging from traffic violations to drug conspiracies, bank robberies to wildlife crimes, domestic violence, and sexual assault to homicides. He is particularly proud to have helped establish the U.S. Attorney’s office’s efforts to combat computer crime and online child exploitation.

In 2003, John was tapped to be legal counsel to Governor Dave Freudenthal, advising on policy development, legislative initiatives, and managing key state programs. He also served as the Governor’s representative for state, regional, and national organizations, including the Western Governors Association, the National Governors Association, and the University of Wyoming Board of Trustees. In the final months of his state service, he was Deputy Director of the Wyoming Office of State Lands and Investments, playing a pivotal role in overseeing millions of acres of state lands and minerals, and culminating with the analysis, negotiation, drafting, and closing of a landmark state land transaction. John reentered private practice by returning to his hometown of Casper and joining with former Wyoming Governor and U.S. Ambassador to Ireland, Mike Sullivan. With Governor Sullivan’s retirement in 2016, John joined Welborn Sullivan Meck & Tooley, P.C., where he has successfully represented large and small clients in commercial and complex litigation, state and local regulatory and permitting matters, and business and estate planning. His extensive trial experience includes both state and federal courts, with appellate work before the Wyoming Supreme Court and Tenth Circuit Court of Appeals.