Wyoming's senior U.S. Senator, Mike Enzi, is hanging up his political spurs after more than two decades in Washington.

Enzi announced his retirement at a news conference in Gillette Saturday morning. He will serve out the remainder of his term which ends in early 2021.

“So far, I have served in the US Senate for more than 22 years,” Enzi said. ”Diana and I have been in Wyoming most weekends often traveling 500 miles by car each weekend. That means I’ve worked in Washington 4 days a week and Wyoming 3 days a week which uses up all of the week. When we have a recess which I call a 'work period' Diana and I usually travel around Wyoming some 1500 miles by car."

Enzi, 75, took office as Gillette's mayor in 1974 during the start of the city's coal boom. During his tenure as mayor, Gillette's population doubled. He served in the Wyoming House of Representatives beginning in 1987 and transitioned to the Wyoming State Senate in 1991.

He was elected to the U.S. Senate in 1996 after former U.S. Senator Alan Simpson retired.

Enzi currently serves on the budget and finance committees.

Before his political career, Enzi worked as a shoe salesman for his father's business in Gillette. He served in the Wyoming Air National Guard from 1967-1973 and was discharged as a staff sergeant.

While in Washington, Enzi was a champion for the coal industry. He was well known for his 80/20 theory in which he argued that most people can agree on 80 percent of issues; it's the 20 percent on which they must find compromise.

Wyoming's junior senator, John Barrasso lauded Enzi's service to Wyoming on Facebook Saturday morning. 

"Mike’s character, courage and credibility have made him a respected moral leader in the U.S. Senate. In four terms in the Senate he has never wavered in his commitment to God, family or Wyoming," Barrasso wrote. "The Senate and Wyoming will miss the valued leadership of the trusted trail boss of our congressional delegation."

Wyoming's lone U.S. Representative, Liz Cheney, also thanked Enzi in a written statement.

“I’m privileged to have had the opportunity to work alongside him for the people of Wyoming and am proud to call him a friend," Cheney said. "He, his wife Diana, three children and all his grandchildren deserve thanks from a state and nation that is indebted to him for his lifetime of service."

The Gillette Republican passed more than 100 bills since he arrived in Washington.