At about 8 p.m. Saturday, 26 vacationing friends and family members from Southern California, ranging in age from 2 to 70, loaded into four vehicles and left Bryce Canyon National Park for the Grand Canyon.

En route, they stopped to see Grosvenor Arch. Then, headed for Arizona, they got stranded on the edge of a 500-foot cliff.

The incident is part of a growing problem of people relying on technology to find a quick route across an area of deep canyons, washes and primitive roads that could be too much even for off-highway vehicles.

In the Saturday episode, the GPS instructed the group to head south, but it would have been better to return to Cottonwood Canyon Road, said Kane County sheriff's Chief Deputy Tracy Glover.

At about 1 a.m. Sunday morning, the group used a cell phone to call for help.

"They were pretty upset and panicking at first, but at about 6 in the morning they were able to give us the coordinates," Glover said.

That was after deputies explained how to use their GPS to determine coordinates. The group was found at about 11:45 a.m. Sunday at Four Mile Bench in northern Kane County.

"All of them were thirsty, but no one was injured," Glover said. Deputies gave the group food, water and fuel.

There are many roads and paths inside the 1.9-million-acre monument, spread across Kane and Garfield counties, and many are not regularly patrolled, said Bureau of Land Management spokesman Larry Crutchfield.

It is not the first time Staircase visitors have unsuccessfully used a GPS to pick a route, Glover said. Since its 1996 creation, dozens have been stranded after following GPS information.

Kane County Sheriff Lunt Smith said people should know a GPS has its limits.

"It's just a piece of equipment that's only as good as the data programmed into it," Smith said. "It can show which direction to go, but not the 500-foot cliff where you can't go any farther."

Crutchfield said many visitors have too much faith in technology.

"The GPS is no substitute for good judgment," he said. "People can start down a nice, graded dirt road and it can soon turn into boulders and deep washes, but they continue driving instead of turning around. I don't understand it. The shortest way is not always the quickest way."

Safety tips

When driving in remote areas on Grand Staircase-Escalante National Monument and other rugged areas:

* Take a cell phone. Service providers are required to allow any 911 call to go through regardless of provider agreements.

* Know how to use and read a GPS, knowing that the devices cannot reveal road conditions or topography and are only as good as the information they contain.

* Always take plenty of food, water, warm clothing, matches, batteries, a spare tire, traditional maps and a shovel.

* Let people know where you are going and when you will return.

* Use common sense. If a road looks too treacherous for the car you are in, turn around.

* Top off the car's gas tank whenever possible. Don't expect to find a gas station in a small town.

* Ask local residents or officials if your vehicle is suitable for particular roads.

* Roads that appear safe when dry can become impassable when it rains.

Stranded

Some recent incidents in which people became stranded on Grand Staircase-Escalante National Monument relying on GPS or other high-tech information rather than their own judgment.

* August: Group of 26 family and friends from Los Angeles relying on GPS got on the wrong road from Grosvenor Arch heading to Grand Canyon National Park and became stranded on Four Mile Bench. The group was able to contact rescuers by cell phone and was rescued without injury.

* May: A couple from Pennsylvania following GPS instructions became stranded on Smoky Mountain Road after an oil pan on their Neon sedan was punctured. They had water, but were stranded for four days before being rescued by a passer-by.

* May 2007: Three women, a man and four children from Belgium became stranded on Four Mile Bench after following a GPS route. The family had to lick condensation off their minivan's windshield for water. The women were able to hike until they were found by all-terrain vehicle riders.

* May 2007: A Connecticut family, following GPS instructions, bogged down in sand near Kitchen Corral Road. They stole a rancher's pickup to try to tow their car out, but ran out of gas. They were rescued by the rancher whose truck they stole when he came by driving in a ranch hand's vehicle.

* April 2005: A couple traveling from Salt Lake City to Phoenix got stuck on Cottonwood Canyon Road after a rainstorm while following a map obtained from an Internet travel company. They were pulled from the mire by Kane County deputies without suffering injuries.

Source: Kane County Sheriff's Office, Bureau of Land Management