John Masterson is from Natrona County and graduated from the University of Wyoming College of Law and began his legal career working for the County and District Courts in Natrona County. He later transitioned into private practice and then became an Assistant District Attorney. Masterson moved on to become a lawyer in the U.S. Attorney’s Office for the District of Wyoming.

In 2003, then-Governor David Freudenthal appointed him to serve as legal counsel and federal/state relations coordinator with the Governor’s Office. In his final months of service to the state, Masterson served as the deputy director of Wyoming’s Office of State Lands and Investments. He participated directly in policy making, oversight and administration of over 3.5 million acres of state surface lands and 4.2 million acres of minerals.

Masterson has been a longtime supporter of the Wyoming State Bar, serving on the Board of Law Examiners, the Board of Professional Responsibility, the Board of Officers and Commissioners, the Civil Pattern Jury Instructions Committee, the Legislative Developments Committee, the Editorial Committee for the Wyoming Lawyer and the Wyoming Lawyer Assistance Program Advisory Committee. He is also a past president of the Wyoming State Bar. Masterson was appointed to the Wyoming Game and Fish Commission in March of 2023 for District #7.