A second day of searching turned up no sign Monday of a Minneapolis man who vanished Saturday in Mount Rainier National Park in Washington state, officials said.

Jeff Graves, 47, had been on a family camping trip with his wife and young son in the park, where his mother worked as a volunteer. About 11 a.m. Saturday, he set out alone for a hike, said Curt Jacquot, a park spokesman.

"We're very hopeful," Jacquot said of the chances that Graves, an experienced hiker, would be found alive even without any overnight gear. "Temperatures have not been too low at night."

Generally, temperatures have stayed at 40 degrees or higher at night for most of the trail, though it could have been near freezing atop Eagle Peak, where Graves was hiking, Jacquot said.

"The trail he went on is 3½ miles one way to the top of Eagle Peak, and it gained 3,000 feet in elevation," Jacquot said. "It's a fairly strenuous trail because of the elevation gain. It goes through the forest for about three miles on switchbacks [zig-zag trails that cut diagonally up hills].

"The last half-mile, the trees get sparse and you're near the top."

In the last section, there's up to 2 feet of snow. If a hiker stays on the trail, there's no danger of dropoffs, Jacquot said. Most people stop where the trail ends, with a spectacular view on a clear day.

It's another 100 to 150 yards to the peak, where the going is steep, rocky and more snowy. That stretch is not recommended by rangers, who want people to stay on the maintained trails.

Andy Yee, a close friend of Graves' since their days at Macalester College in St. Paul, said he doesn't believe Graves would attempt to climb beyond the trail's end.

"I don't think he was equipped to get to the peak," Yee said. "It's more of a family camping trip than anything else."

Monday afternoon, park rangers called Yee as they compiled a profile of Graves in an attempt to track how he moved and might negotiate difficulties.

"He's pretty quick-thinking on his feet," Yee said, "but if he fell or if he's injured, all bets are off."

Hours earlier, Graves' wife, Randi, had called Yee from Washington state to tell him that Jeff was missing. She was keeping vigil at the park Monday night along with the couple's 7-year-old son, Connor, and Jeff's parents.

Water plentiful

Jeff Graves' mother, Ruth, told rangers she last saw him about 11 a.m. Saturday, when she dropped him off near the Eagle Peak trailhead. He wore a red Gortex jacket, a tan baseball cap, long tan pants, a gray fleece shirt and leather hiking books.

Rangers figure that Graves was carrying water in his small blue daypack. But there's also plenty of streams to drink from while hiking on Eagle Peak, Jacquot noted.

That hike would typically take four to six hours. Night falls there by 9:30 p.m. Graves' mother reported him missing when he failed to return to Longmire, a developed area of the park near the trailhead, on Saturday evening.

On Sunday, about 40 rangers and volunteers, plus two dogs with their handlers, searched all areas surrounding Eagle Peak, splitting into teams. On Monday, a thick fog lifted by 11 a.m. and a helicopter set out to scour the mountainside. The number of searchers grew to 50, plus the canine teams, led by rangers.