Rescue workers continued Tuesday to search the Superstition Mountains in triple-digit heat for three Utah men who went missing while looking for the stuff of legend.

Lost Dutchman Park

Families of the missing said the men planned to search the mountain range for the fabled Lost Dutchman Mine that, according to folklore, was discovered by an Old West prospector somewhere in the wilderness east of Apache Junction in the latter 1800s.

A look back: 2 missing hikers found in Superstitions

Curtis Merworth, 48, Ardean Charles, 67, and Malcolm Meeks, 51, have been in that wilderness since at least Sunday, when they were reported missing.

Their vehicle � a silver, Saturn VUE hybrid with Utah plates � remains parked at the First Water Trailhead, a staging area at the end of three miles of winding, unpaved road off Arizona 88. Authorities think it has been there for days, possibly longer; family members last heard from the trio July 6.

Up to five helicopters, 20 law enforcement personnel and 100 volunteers, some on horseback or with canines, have aided in the search and rescue mission. A search coordinator said rescue workers have covered more than 100 miles on foot, both from the trailhead and from helicopter drop-off points.

The search area extends to nearly the horizon, one official said. No one knows where or how far the men planned to go.

Taped onto a board outside the command center were photos of the missing and physical descriptions. It also said that authorities didn't know what type or color of clothing the men were wearing or whether they had provisions.

Officials think the men may not have had enough food or water, considering they planned to stay in a hotel and hike the area by day.

Sgt. Jesse Spurgin of the Maricopa County Sheriff's Office, which is leading the effort, said rescuers are "still under the assumption these gentleman are alive and still hoping to find them in at least fairly good health."

Mesa Mounted Posse volunteer David Salerno doesn't share his optimism. Salerno and his horse, Geronimo, searched an area where footprints were located on Monday but found no sign of the hikers.

"There's only a couple of places with water out here. You've got to be prepared," he said. "If they knew where they were going, if they had a plan, nobody knew about it."