After going roughly 10 hours without a drink in the 100-degree heat, he finally dropped dead of thirst, face down in the dirt, less than 100 yards from the goal: a cave with a pool of water.

But Buschow was no solitary soul, lost and alone in the desert. He and 11 other hikers from various walks of life were being led by expert guides on a wilderness-survival adventure designed to test their physical and mental toughness.

And the guides, it turned out, were carrying emergency water on that torrid summer day.

However Buschow wasn't told that.  He wasn't offered any water for a reason - the guides did not want him to fail the $3,175 course.

They wanted him to dig deep, push himself beyond his known limits, and make it to the cave on his own.

The family members were furious.

"Down in those canyons it's like a furnace," said Rob Buschow of Glen Spey, N.Y.

"I don't have my brother anymore because no one would give him water."

Garfield County authorities declined to file charges, saying there was insufficient evidence the school acted with criminal negligence. The prosecutor said participants knew they were taking a risk.

The U.S. Forest Service, however, has stopped BOSS from using Dixie National Forest for a portion of the 28-day course this summer until it gets outside advice on providing food and water.

The agency said it was the first death of a participant in a BOSS survival exercise.

BOSS emphasizes personal growth through adversity, and using your wits to survive. The mantra: "Know more, carry less."

Tent, matches, compass, sleeping bag, portable stove, watch — all have no role. Campers are equipped with a knife, water cup, blanket and poncho and are told they could lose 20 pounds or more. Among the things they learn is how to catch fish with their hands and how to kill a sheep with a knife.

The course is intended to push people "past those false limits your mind has set for your body."

"Somewhere along the many miles of sagebrush flats, red rock canyons, and mesa tops of Southern Utah — somewhere between the thirst, the hunger and the sweat — you'll discover the real destination: yourself," BOSS says on its Web site.

Buschow had marched the arctic tundra in Greenland. And after leaving the Air Force, he worked security at U.S. bases outside the country. He recalled his days as a Boy Scout in his May 2006 application to BOSS.

The documents obtained by the AP disclose the brief but bitter wilderness adventure of Buschow:

On July 16, he gathered here with the 11 others, including some from England and a college student who had bicycled from Maine. Most were in their 20s and 30s. They ran 1 1/2 miles so the staff could assess their conditioning.

Buschow "was not the most in-shape but not the most out of shape either," recalled camper Charlie DeTar, 25, the cross-country bicyclist.

On the second day, after a cool night, the group set out around sunrise and stopped about 8:30 a.m. to dip their cups into Deer Creek in what turned out to be the only water until evening. Buschow pulled a bottle from his pack — but was warned by the staff not to fill it.

During the early phase of the expedition, participants can drink water at the source only and cannot carry it with them.

The group, led by three guides, formed a loose chain, with stronger hikers ahead of people struggling at the 6,000-foot elevation, or more than a mile above sea level.

"We didn't cover all that much distance, maybe five to six miles. We were moving slowly, a lot of up and down," DeTar said in an interview from Vermont. "You don't have food, you don't have water, so you have to move at the slowest pace of the group."

Not everyone had close contact with Buschow, but a consensus emerges from the campers' written accounts obtained by the AP: While cheerful, encouraging and coherent at times, he was a man in deep trouble hours before he collapsed.

"We were all desperate for water," a camper wrote. "Every time (Buschow) would fall or lie down, it took a huge amount of effort to pick him back up. His speech was thick and his mouth swollen."

"This was the first point at which I became concerned knowing that delirium happens when dehydration becomes severe," a camper wrote. Buschow "also asked if there was much air traffic that went through here, and asked if anyone had a signal mirror."

(The Forest Service, citing privacy concerns, deleted certain names from documents.)

By 7 p.m., as the sun descended and temperatures cooled a bit, the group approached a cave in Cottonwood Canyon, known to BOSS guides as a reliable source of water.

Buschow's companions were carrying his possessions for him. Within earshot of people exhilarated about the pool of water, he collapsed for the last time.

"He said he could not go on," staff member Shawn O'Neal wrote two days later in a statement ordered by the Garfield County Sheriff's Office. "I felt that he could make it this short distance and told him he could do it as I have seen many students sore, dehydrated and saying 'can't' do something only to find that they have strength beyond their conceived limits."

O'Neal didn't inform Buschow about his emergency water.

"I wanted him to accomplish getting to the water and the cave for rest," he wrote. "He asked me to go get the water for him. I said I was not going to leave him. ... Shortly thereafter I had a bad feeling and turned to Dave and found no sign of breathing.

DeTar, a camper who performed CPR, said no one was told that BOSS guides carried emergency water, but "I heard it slosh" in a pack.

Should the water have been offered to Buschow? And if it's for an emergency, what triggers it?

"Hard to say," said DeTar, who has a master's degree from Dartmouth College and is trained in wilderness first aid. "One thing that BOSS offers you is an opportunity to push yourself physically into the red zone. ... He was 200 feet from the water.  Is that the point where you give it to him? Or 500 feet?"

Bernstein, the school's owner, agreed to answer questions only by e-mail. He said BOSS instructors can give water based on their assessment of a camper's needs.

"The group appeared to be within the normal parameters we've seen on the trail over the years," Bernstein said. "Many hikers were, understandably, tired, but morale was high and the participants were determined to continue. ... He seemed capable of completing the hike to camp that evening."

In a Feb. 27 letter to the Forest Service, Bernstein said Buschow may not have trained properly, pointing to comments he made to another camper about drinking a gallon of water a day and eating cheese steaks to bulk up before the expedition.

His brother, Rob Buschow, said: "It's sickening when they blame the victim."