PHOENIX – Larry Dever, the four-term Republican sheriff of Cochise County who was an outspoken advocate for stronger border security, has been killed in a one-vehicle crash near the northern Arizona town of Williams. He was 60.

Dever’s death was confirmed Wednesday by the sheriff’s department.

Dever was driving on a dirt Forest Service road on the way to meet family members for a camping and hunting trip at White Horse Lake south of Williams when his pickup rolled, according to the Coconino County Sheriff’s Office.

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.

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

Dever was first elected to his post as the head of the county’s law enforcement agency in 1996, and was last re-elected in 2008. He joined the agency as a deputy in 1976, according to the sheriff’s department website.

He entered the national spotlight as one of Arizona’s four border sheriffs who asked to legally defend the state’s controversial anti-illegal immigration law in federal court. Cochise County, in the state’s southeastern corner, shares an 83.5-mile border with Mexico and is one of the state’s hot spots for illegal immigration and drug smuggling.

He said at the time that the federal government was failing to secure the border and praised the law, which includes provisions that require police to question a person’s immigration status while enforcing other laws and if officers suspect the person is in the country illegally.

“If the federal government had been doing and would continue to do its job in securing the border here in southern Arizona, this would not be an issue. Unfortunately, they failed to do that, so Arizona stepped up and said, ‘We want to be partners. Here’s a role we think we can play,”‘ Dever said earlier this year.