As of Monday afternoon, Ryan Shankles, David Yoder and Miguel De La Torre still hadn't been found. The search has subsided for the day and will resume at daybreak Tuesday, said San Bernardino County sheriff's spokeswoman Jodi Miller.
Searchers spent several hours searching for the missing men on Sunday, but halted the search overnight.
"They searched until sunset Sunday and Monday night and they're scheduled to be out again tomorrow morning," Miller said.
Four men initially set out on the hike Sunday morning from Fish Creek Trail. A vehicle belonging to one of the men was found in the parking lot near the trail, Miller said.
One of the hikers, James Goins, turned around and headed back down the mountain about two hours into the hike.
He called sheriff's deputies when the other men didn't return.
Searchers from the Sheriff's Department and the U.S. Forest Service looked for the men, but couldn't find them. They resumed their search at 6:30 a.m. Monday, setting up a command post at Heartbar Campground, north of where the men left on their hike.
Miller said the men are experienced hikers and had food and water.