GREEN VALLEY, AZ - A man who lost control of his all-terrain vehicle while riding in the southern Arizona desert has died.
The Pima County Sheriff's Office says deputies responded Saturday around 11:40 a.m. to an area near Green Valley, about 10 miles southwest of Mission and McGee Ranch roads.
They say 68-year-old Terry Duncan and a friend were riding when Duncan lost control and hit his head.
The friend attempted life-saving measures but Duncan was unresponsive.
Authorities say Duncan was not wearing a helmet. Neither alcohol nor drugs is believed to be a factor in the incident.