Judge Mahan is a longtime resident of Las Vegas, having lived and practiced law there continuously since 1973. He was born in El Paso, Texas, during the Second World War and he grew up in Grand Junction, Colorado.

Judge Mahan attended the University of Charleston, West Virginia, and following graduation, he served in the United States Navy from 1966 to 1969.

Upon receiving his honorable discharge, Judge Mahan attended Vanderbilt University Law School where he was selected for Vanderbilt’s national moot court team. Following graduation from law school, Judge Mahan was admitted to practice in Nevada, the Ninth Circuit Court of Appeals, the United States Tax Court, and the United States Supreme Court.

In 1982, Judge Mahan and Frank A. Ellis, III formed the law firm of Mahan & Ellis, Chartered, where they practiced law primarily in the areas of business and commercial litigation for seventeen years. Judge Mahan was named to “Who’s Who in America” and “Who’s Who in the World,” as well as “Who’s Who in American Law.”

In February 1999, Governor Kenny Guinn appointed Judge Mahan to the Clark County Eighth Judicial District Court. Judge Mahan served as chair of the Committee to Review and Revise the Eighth Judicial District Court Rules, as chair of the Clark Regional Judicial Counsel, as a member of the Joint Task Force on Civil/Criminal Specialization, and was appointed by the Nevada Supreme Court to the Study Committee to review the Nevada Rules of Civil Procedure.

In 2001, United States Senator John Ensign nominated Judge Mahan to the United States District Court. Judge Mahan formally took the Oath of Office on February 1, 2002.