Sunday's successful helicopter rescue of a man stuck in the Piute Mountains east of Bakersfield was a milestone of sorts.

It was the first time a personal locator device tipped off local rescue personnel to an actual emergency, said Sgt. Mark Baldwin of the Kern County Sheriff's Office.

When used correctly the devices can be lifesavers, Baldwin and others say.

But search-and-rescue crews stuck with responding when adventurers push the come-get-me button say some folks are using the gizmos as a crutch instead of preparing adequately for expeditions.

Baldwin, who led the search and rescue team that helped get 34-year-old James Coop of Bellflower to safety, said the department has previously responded to two false alarms triggered by the locator devices.

A group of offroaders in the Jawbone Canyon area who'd bought a unit decided not to take it on their ride until they had more time to study the manual, Baldwin said. They thought they'd turned it off before they tossed it in a truck, but instead had activated the emergency signal. Deputies had to research vehicles registered to the men to pick out the right truck in the parking area and verify the call was a false alarm.

A second device found pinging in the desert had been lost by an owner who discontinued service. Someone apparently ran across it and turned on the distress signal.

Search and rescue crews spent half the night tracking the unit down, Baldwin said.

Sunday's mission, however, showed the devices can work as intended and make rescuers' jobs easier.

Coop, who could not be reached for comment Monday, was an experienced outdoorsman, according to a friend reached by phone Sunday.

He'd been stuck in deep snow and mud since Saturday morning before he pushed the help button Sunday.

Coop was using a satellite-based SPOT device that's come on the market in the last few years, Baldwin said. The units, which require an annual subscription fee of $100 or more, route distress calls through a private company that contacts the appropriate emergency agency and provides responders with the subscriber's itinerary, emergency contacts and other information.

Another type of device known as a "personal locator beacon," or PLB, has been in use longer and routes satellite-based distress signals through government channels.

In Coop's case, the private company contacted the California Emergency Management Agency, which in turn reached the local sheriff's office. Sheriff's staffers reached Coop's family and were able to confirm he'd been adventuring here and would only activate the device if he needed help.

Sgt. Tim Melanson, who oversees the sheriff's air unit, was on board Sunday when the Huey II plucked Coop from the mountains.

The locator unit had sent out such accurate data about Coop's whereabouts that Melanson decided to send out the Huey right away. Usually, smaller helicopters that use less fuel first scout out a victim's location before the rescue craft goes up.

"I decided to send up the big ship, and it paid off," Melanson said.

Fuel costs for Sunday's mission were about $450, he said.

Matt Scharper of the California Emergency Management Agency coordinates search and rescue operations for the state. He coined a term for the devices last fall that seems to have stuck: Yuppie 911.

"These devices are very valuable to an educated user," Scharper said.

But some people have taken undue risk because they assume they'll be rescued if they get in trouble.

Statewide, rescue crews respond to the devices about once every two weeks, Scharper said.

The units only send a call for help. Updates aren't available, nor are details on the situation.

"It's free to the victim," Scharper said, though a Blackhawk helicopter rescue costs taxpayers about $3,000 an hour.

Still, Scharper doesn't think victims should be charged, as cost worries might keep some people who need help from asking for it in time.

The most important thing is for adventurers to prepare adequately for their outing, Scharper said. Research weather conditions, bring food and water, wear the right clothes and share your itinerary with loved ones -- and don't do anything you wouldn't do if you didn't have the unit.

"People need to be prepared," he said. "Don't rely on these devices."