Two men were critically injured when they and a third friend crashed on an all-terrain vehicle Friday in a remote area near Armstrong Woods and Guerneville, authorities said.

The ATV apparently overturned at the top of a hill on private property near McCray Ridge Road, throwing the trio off before the motorized vehicle continued rolling almost a quarter of a mile down a steep slope, emergency personnel said.

The man most seriously hurt in the 12:30 p.m. crash was flown to Santa Rosa Memorial Hospital aboard the Sonoma County sheriff's helicopter after being plucked to safety at the end of a 100-foot cable, pilot Paul Bradley said.

He was later loaded into the aircraft and flown to the hospital while paramedics prepared a second critically injured patient for ground transport to Memorial, Bradley said.

Their names were not released because of patient confidentiality laws.

A third man was uninjured, Bradley said.