A manhunt was on in Northern California early Wednesday after a volunteer searching for a 75-year-old hiker was shot and wounded by an unknown attacker.

The rescuer, identified as 69-year-old Steve Wolf, was in stable condition with a hip wound, operations captain for the Nevada County Sheriff’s Office Paul Schmidt said. Crews late Tuesday took the rescuer to a site where a helicopter could land to transport him to a hospital.

The three volunteers with the Placer County Search and Rescue team were among several groups looking hiker Timothy Hansston, who was reported missing along the South Yuba River about three miles outside the rural town of Washington, the Sacramento Bee reported.

The seach for Hansston was called off around midday Wednesday,KCRA reported, but the manhunt for the shooter continued.

The town of Washington is about 75 miles west of Reno, Nevada.

Schmidt said it wasn't clear what prompted the shooting.

"We have absolutely no information on who or why," he told the Associated Press.

Nevada County Sheriff Keith Royal said helicopters with heat-detecting sensors searched for the shooter.

"Please keep Steve Wolf and his family in your thoughts, along with the deputies tasked with bringing the suspect to justice," the Placer County Sheriff's officials said.

The Associated Press contributed to this report.