A man climbing California’s Sierra Nevada mountain range came dangerously close to a deadly fall after becoming stranded on a six-inch ledge more than 10,000 feet above the ground.

Rob Martin was scaling the Mendenhall Couloir, a gully on the face of Laurel Mountain, with a friend last Saturday, a route that is steep with sections of loose rock that often become unstable.

The section the experienced climber was traversing had no route markers, according to the San Francisco Chronicle.

The big mistake he made was veering off course. The Mono County Search and Rescue team explained why doing so could quickly become deadly.

“Traveling off-route quickly leads to increasingly vertical, un-protectable 5th-class terrain with no viable means of continuing either up or down.

“With thousands of feet of vertical exposure below, any fall would almost certainly be fatal,” the volunteers wrote in a Facebook post last weekend.

Martin told NBC News how he felt during the dramatic rescue: “A lot of scary thoughts. A lot of lonely thoughts. My hands were cramping. The feet were the hardest part, they’re only half of the ledge.”

After rescuers were alerted about the stranded climber, they immediately began searching for him. The team spent about two hours looking after being notified by the sheriff’s office but could not locate him, the New York Times reported.

Then, rescuers finally heard a voice calling from somewhere in the distance.

When they located the climber, rescuers noticed he was repeatedly shifting his weight from one foot to the other, a sign his legs may have been cramping.

With the man stuck on such a narrow ledge, the team feared he might not be able to hold his position much longer.

“It was determined that, without intervention, a fatal fall was increasingly possible if the subject remained in place overnight,” the rescue team wrote.

Powerful winds ruled out using a helicopter hoist to pull him from the mountain, forcing rescuers to make their way toward him on foot in the dark, relying on headlamps to navigate the terrain, video footage shows.

“It was incredibly dangerous and a little scary moving around in the dead of night – everyone’s operating on pure trust,” rescuer Mitchell Quiring told the Chronicle. “It’s navigable terrain during the day but it becomes unnavigable at night.”

But after seeing how precarious the climber’s situation was, Quiring said leaving him there until daylight was not an option.

One rescuer eventually approached the man from above and secured him to a rope system, eliminating the immediate risk that he could fall. By that point Martin had spent 8 hours clinging to the steep cliff.

The rescue, which went on for about 15 hours, continued into the early hours of Sunday morning before the operation was finally completed.

“He did not give up, and that is really one of the biggest takeaways from this,” Quiring told the New York Times. “This could have been a very different story if he didn’t push through the adversity.”

Martin also had a message for his rescuers during his interview on NBC News.

“My message to Mitch and his team is thank you for saving my life,” he said. “I would not be sitting here if it wasn’t for them and their sense of service.”