Former Congressman Bill Orton, a political maverick who served three terms as a Democrat in one of Utah's most conservative districts, has died.

The 60-year-old died in an all-terrain vehicle accident Saturday afternoon at the Little Sahara Sand Dunes, the Juab County sheriff said.

"He was riding out on the sand and went off a very steep sand dune, and when he impacted the bottom, the front end of the four-wheeler flipped on top of him, injuring him," Sheriff Alden Orme told the Deseret News late Saturday. "He was alone at the time of the accident. Another ATV rider passed by a short time later and found him."

Ambulance crews and a medical helicopter were dispatched to the scene but arrived too late.

"He succumbed to his injuries," Orme said.

Orton was wearing a helmet, the sheriff said.

Orton's wife, Jacquelyn, made a brief statement about her husband's passing on her Facebook profile.

"I must go meet my children, who were with their father, in Provo as quickly as possible. Please excuse the crassness of this announcement," she wrote. "Please keep us in your prayers."

Political colleagues and opponents were shocked by Orton's sudden passing. Karen Hale, the former state senator who was Orton's running mate during the 2000 governor's race, cried at hearing the news.

"It's just awful," she said. "His boys ... that's just what is breaking my heart."

Utah Democratic Party Chairman Wayne Holland said his prayers were with Orton's wife and sons, Will and Wes.

"It's a big loss for Utah," he said. "These things are surreal to me. Life ... I don't know what to say."

Orton served the 3rd District from 1991 to 1997. He was an anomaly as a Democratic congressman representing one of the nation's most conservative districts.

Orton described himself as someone who hated politics, hated campaigning and hated fundraising. He said partisanship made politicians less effective. His first election to Congress surprised almost everyone but him, including most voters. He had trailed in polls significantly during the entire campaign as a Democrat in possibly the most Republican district in the nation.

On the weekend before the election, his Republican opponent ran a newspaper ad showing himself and his large family next to a mug shot of Orton, who was single, which said, "Bill Orton and his family." The ad — intending to show the GOP opponent was more family friendly? — backfired. Voters viewing it as an insult to single people voted in droves for Orton, making his win perhaps the biggest upset ever in Utah political history.