Cochise County Sheriff Larry Dever was killed in a car crash Tuesday night, authorities report.

The four-term Republican sheriff was on his way to meet one of his six sons when his vehicle rolled outside the northern Arizona town of Williams, according to Cochise County Sheriff's spokeswoman Carol Capas.

The Associated Press reported that another driver had been following Dever's truck Tuesday evening and told deputies he came around a corner and found a cloud of dust. The pickup had rolled but landed on its wheels. Dever was dead at the scene.

Coconino County sheriff's spokesman Gerry Blair told the AP it was not clear if Dever was wearing a seat belt, but he was not ejected. There was no sign Dever had been drinking.

The Sheriff's Department released this statement:

"It is with deep sadness and regret that the Cochise County Sheriff's Office must advise the following: Sheriff Larry Dever was involved in a one vehicle accident near the town of Williams on Tuesday September 18, 2012 at approximately 7:00 pm. As a result of this accident Sheriff Dever was fatally wounded and did not survive. The Coconino County Sheriff's Office is in charge of the investigation."

Dever was 60 years old and was born and reared in St. David, in Cochise County. He served 20 years as a sheriff's deputy before he was elected sheriff in 1996. Dever was re-elected three times and was running unopposed in this fall's election.

The Sierra Vista Herald reported Wednesday that Dever and his wife, Nancy, are the parents of six sons. The oldest serves as a major in the U.S. Army, three work for Arizona law enforcement agencies, one as a firefighter, and one attends college.

The sheriff died just four days after his 86-year-old mother, Annie Mae Dever, died of cancer.

Dever appeared on Arizona Public Media programs twice this summer related to immigration and Arizona's law, SB 1070.

Watch a June 29, 2012 Washington Week Online Town Hall, featuring Dever, above.

Watch a June 25, 2012 Arizona Illustrated special report on the U.S. Supreme Court's SB 1070 decision, featuring an audio interview with Dever, below.