PROVO -- Thanks to a band of modern-day raiders, no one will really know how a tribe of Indians dwelt in a cave in the northern LaSal Mountains some 8,000 years before European explorers set foot in America.

"Only rarely do we come across a site like Polar Mesa Cave that can tell us so much about how prehistoric people lived and adapted over such a long period of time. A large chapter of Utah's fascinating history has been destroyed forever. We'll never know what happened there thousands of year ago," said Stan McDonald, archaeologist for the Manti-LaSal National Forest.Archaeologists, though, know what happened there between 1986 and 1991: Vandals excavated and looted the southeastern Utah cave, stealing about 500 artifacts and some burial remains.

And thanks to modern-day archaeological sleuth David Griffel, authorities know who made off with chipped stone tools, basketry, plant fiber sandals and leather clothing and pouches the Anasazi or perhaps Fremont Indians left behind.

Griffel, a Provo-based U.S. Forest Service special agent covering the Uinta, Manti-LaSal and Fishlake national forests, cracked the largest Archaeological Resources Protection Act caper in the United States. He led a team of local, state and federal investigators whose five-year probe resulted in 18 felony convictions against 10 people.

The scope of the case drew nationwide media and legal attention. It also earned Griffel, 45, recognition as the Forest Service's special agent of the year for 1998.

"I've been told by experts in the field that these cases are harder to investigate than murders," McDonald said.

Griffel, one of only two Forest Service detectives in Utah, said he's not sure about that because he's never handled a murder case. But he'd never taken on an archaeological heist either.

"I wouldn't say it was more difficult, but it definitely was a very complex case," he said. "We employed a lot of the same techniques and technology as the Provo Police Department would employ if they were investigating a homicide in downtown Provo."

Some beer and soda cans, food containers and a big hole in the ground in the middle of nowhere comprise most of what Griffel had to go on when the U.S. Attorney's Office assigned him the dead-end case of high desert piracy in November 1994. There were no eyewitnesses, only rumors circulating around Moab and Grand County.

The looting had stopped by the time Griffel began poking around. The worst damage was done from 1989 to 1991 when vandals excavated 54 cubic yards -- about 20 pickup truck loads -- of dirt and rocks from cave.

Griffel gathered up the garbage and some files from the previous investigator and went to work on the case that consumed nearly all of his time the next five years. He and his team rounded up about 30 people whom they believed might have heard something about the stolen artifacts. At least two of them turned into suspects who decided to cooperate with authorities.

Investigators initially pieced together the crime on circumstantial evidence and were able to corroborate it with more tangible clues, said Griffel, a 22-year Forest Service veteran.

Through the interviews, investigators learned the pothunters had taken photographs during their illegal digs. Griffel obtained them to identify suspects. The FBI crime lab in Washington, D.C., found latent fingerprints on some of the trash and was able to link them and some DNA evidence to the suspected thieves.

"Dave's a heck of an investigator. He pursued the case for five years for us. It was long hours and lots of overtime. Lots of interviews, lots of time on the road," McDonald said.

Investigators recovered a large collection of artifacts from the pothunters, who were in it as a hobby rather than for commercial gain. Some items such as arrowheads were pawned. The remainder are on display in a Cedar City museum. Archaeological damage is estimated at $500,000.

The Polar Mesa Cave investigation piqued Griffel's interest in American Indian history and the remnants of their lives. It upsets him that treasure seekers "don't give a hoot about the context" of what they're digging up. All they want is artifacts to hang on a wall, he said.

"I developed a real fondness for those sites and how important and critical they are," he said. "It has given me a real appreciation for the science of archaeology and its value."

Griffel recently obtained indictments against four more pothunters on Forest Service and Bureau of Land Management property in the St. George area. He's currently working of four other archaeological cases throughout the state.