RIO VERDE, Ariz. (AP) — Authorities say a 58-year-old man has died while dirt biking at the Tonto National Forest near Rio Verde.

The Maricopa County Sheriff's Office says deputies responded to a medical call in the desert area northeast of Rio Verde around 9:30 a.m. Saturday.

The caller told deputies that he and two others were dirt biking a trail when one of them started to feel sick.

Sheriff's officials say paramedics performed CPR on the man, but he died at the scene.

His name hasn't been released yet.

Authorities say it's unclear if the death was a heat-related incident or a medical issue.