Former US Senator Mike Enzi has died at 77 following a bicycle accident over the weekend.

Enzi's son, Brad Enzi, tweeted that his father was life-flighted following a bicycle accident on Saturday. 

The former mayor of Gillette when the town underwent its coal boom, Enzi was elected to the United States Senate in 1997. He retired in January.

In his farewell speech on the US Senate Floor earlier this year, Enzi said it was never his intention to get into politics.

But a chance meeting with then US Senator Al Simpson at a leadership conference in Cody changed that. Simpson was the keynote speaker at the event.

"I don't even know what party you're in, but it's time you put your money where your mouth is on this leadership stuff and get into politics," Simpson told Enzi. "That town you live in — Gillette — needs a mayor."

At the time, Gillette's population was skyrocketing, and "city services were not keeping up."

During his more than two decades in the Senate, Enzi prided himself on his 80-20 philosophy.

"People sometimes think compromise is the answer. I think it means, I give into something I don't like and you give into something you don't like and we both end up with something neither of us likes," Enzi said.

He was 77.

This story will be updated.