Exploring the desert near Green River, Larry Walker stumbles across fossilized dinosaur bone on a plateau. The find sparks a three-year illegal mining operation on federal land to learn about his find. Torn between keeping his discovery a secret and needing money, Walker begins to sell bones on the black market. These unusual bones soon attract the attention of law enforcement agents and paleontologists.

James Kirkland's infatuation with dinosaurs bursts forth whenever he talks about any of the new species he has helped unearth.

He can be tough to stop once he dives into details of his discoveries, some of which have made him a little famous.

The vicious killing machine Utahraptor was Kirkland's discovery, announced soon after "Jurassic Park" made a related dinosaur, Velociraptor, famous.

While working in Colorado, the man who has been Utah's state paleontologist since 1999 also helped exhume a New Mexico therizinosaur, the first North American member of the claw-wielding dinosaur family whose members included a Godzilla-esque beast.

Stories emerging from western gem and mineral shows indicated someone was selling bones that sounded similar to Kirkland's New Mexico therizinosaur. He encouraged friends and colleagues to ask around about the origins of these bones.

His determination to learn more intensified in early 2001 after a friend gave him a box of the bones from a sympathetic dealer, and Kirkland was able to touch the elusive beast for the first time.

Rummaging through the box, bits and pieces had identifiable ends, but without knowing the bones' origin, they were useless - a consolation prize.

"The rumor was that the guy was not going to dig the site anymore because the heat was too high," he said.

If the fossil thief slipped away, Kirkland might never find the site. Narrowing the search to the Cedar Mountain formation still left a daunting slice of Utah to cover.

To make matters worse, another paleontologist seemed poised to find the dinosaur.

While still in Colorado, years before the therizinosaur rumors started to percolate, Kirkland introduced Denver paleontologist Ken Carpenter to the formation's wonders.

Carpenter's group calls itself the "Hordes From the East." The tongue-in-cheek nickname refers to his Denver Museum of Nature and Science group that had spent the past decade sweeping across the formation.

Carpenter, like Kirkland, heard the therizinosaur stories. If the beast sat on their path, the Hordes would find it.

But Carpenter didn't share Kirkland's passion for finding this new dinosaur. If the Denver team unearthed the dinosaur, it would be a bonus. The group sought a thorough and scientific search of the formation.

During their southern Utah march, the Hordes uncovered a number of new species, including members of the armored, tank-like dinosaur family Gastonia.

Kirkland, though, eyed Carpenter as competition, regardless of his intent. As long as Carpenter's team worked the Cedar Mountain formation, it ranked as the favorite in the therizinosaur derby.

Despair began to settle in until Kirkland caught a lucky break.

At a Colorado dinosaur symposium in 2001, Kirkland met John Scandizzo, a retired California doctor. Scandizzo, who ran a business in Colorado creating dinosaur fossil casts, told Kirkland he had information about southern Utah's disappearing dinosaur.

"His eyes lit up," Scandizzo said. "He knew what the stuff was."

Scandizzo had met Larry Walker, the man who spent three years illegally digging the dinosaur, at a gem show. Walker later approached Scandizzo with a problem.

Walker wanted to turn over the dinosaur to science without revealing his identity. The potential scientific value of this dinosaur find weighed on his mind, even as he sold what he considered extra bones at the shows.

Scandizzo agreed to help Walker.

"My interest in this was to make sure the fossils . . . did not get further into the hands of private collectors," Scandizzo said.

Beyond trying to salvage the science, he also saw a business opportunity. Scandizzo and Walker wanted to secure the rights to cast and sell replicas of this potentially important dinosaur.

Though Kirkland said he couldn't assign the casting rights, he and Scandizzo exchanged numbers. Eventually, Scandizzo called with GPS coordinates.

With an excited group of University of Utah graduate students and volunteers, Kirkland trekked into the desert and blanketed the location. Searchers radioed details of any bones to Kirkland for evaluation. None led to a therizinosaur.

"[Kirkland] was the last one back to the truck that day," volunteer Joe Gentry said. "You could tell he really wanted the site bad."

The visit frustrated Kirkland. Surely, a site producing so much black market material would be peppered with excavation pits screaming, "Therizinosaur here!"

Kirkland called Scandizzo to learn one of the GPS coordinates was off by a single digit, which put him a mile away.

Later that summer, driving in southern Utah, Kirkland headed to the coordinates with his 12-year-old daughter. Kirkland left her in the truck, saying he would be right back.

About four hours later, Kirkland returned finding no bones, no holes, no nothing.

Even with the exact GPS readings, Kirkland came up empty. Disappointment mounted as he called Scandizzo to explain he couldn't find this site.

Scandizzo relayed Kirkland's problem to Walker.

Walker had hoped it wouldn't come to this, but if he wanted to turn this dinosaur over, he faced his final option.

glavine@sltrib.com