On the morning of June 11, Lukas McClish stopped by the home of a friend who told him about a granite outcropping in the nearby woods that piqued his interest, so Mr. McClish set out on his own, shirtless, to explore the scenery.

Mr. McClish, 34, of Boulder Creek, Calif., would not be seen or heard from for nine nights and 10 days. His disappearance into California’s Big Basin Redwoods State Park would prompt a search that involved about 300 people, emergency personnel from several agencies and ended with help from a dog.

Mr. McClish, a hiker who does landscaping in forests that have been razed by wildfires, appeared to have been swallowed by the woods.

“I was just so astounded by being lost,” he said in a telephone interview.

The area where Mr. McClish was lost had been hard-hit by the C.Z.U. Lightning Complex fire in 2020 and “looks completely different from all of the other terrain,” he said.

“That’s one thing that I didn’t take into consideration — when the fire comes through like that and decimates it, it turns into the desert, and you’re unable to find your bearings,” he said.

Typical markers to gain a sense of direction, like deer trails or hiking paths, were gone. But Mr. McClish, an experienced backpacker who has traversed other rugged regions of the United States, took it as an opportunity to explore a part of his backyard that he was unfamiliar with.