Dina Mishev is a writer for The Washington Times.

It's 103 degrees in the vegetation-starved badlands outside Great Falls, but no one is even eyeing the shade of a tarp strung up 20 feet away. How could we when a 150-million-year-old stegosaurus is at our feet, ready for excavation?

It has been a long time--decades, really--since dinosaurs adorned my bed pillows and were doodled in the margins of my science textbooks, but I jumped at the chance to come, as an amateur paleontologist, to Montana, where the country 's first dinosaur fossils were found in the mid-1850s. Visions of a "Jurassic Park"-meets-Smithsonian vacation (minus the death aspect) swirled in my head.

Institutions and museums throughout the state invite paying volunteers of all ages to help unearth everything from Griffen, the 150-million- year-old stegosaurus, to maiasaur nesting sites, troodon eggs, daspletosaurs, and even Tyrannosaurus rexes.

I spent time with two: the Judith River Dinosaur Institute (JRDI), the organization excavating Griffen, and the Old Trail Museum, not the site of a large-scale dig, but where I could have the chance to make a large discovery of my own.

On these expeditions, volunteers get to do nearly everything--the cool stuff, at least, the real paleos do: lie in the dust, brushing, chipping, and blowing away at the accumulated detritus of tens, even hundreds, of millions of years; help cast retrieved bones; and prospect for new sites.

Youngsters return home actually hoping teachers will assign the what-I- did-for-summer-vacation essay. I return home wondering if it is too late for a career change.

At the moment, I, with a dozen others ranging in age from 14 to post- retirement are in Rick and Linda Yurek's back yard with the JRDI. The Yureks found Griffen four years ago. It's named after the now-defunct Griffen Mine, which we pass on the 20-minute drive out to the Yureks' ranch from Great Falls.

Yurek was digging in his yard, a stone's throw from the front porch, to put in a retaining wall when his son Cody, then 17, noticed a large grayish-brown something protruding from the freshly exposed earth. Cody wiggled it around a bit and finally pulled a football-size hunk of rock out of the ground. It looked like a dog bone, but it was the bottom end of a stegosaurus tibia--not that the Yureks knew it at the time.

The retaining-wall project was put on hold. Though the Yureks didn't know any specifics about their discovery, "You could tell it was definitely old," Yurek says.

It took three years for a dino diagnosis, but when it came, it was big. Jack Horner, a Montana-based paleontologist who was the model for the character Alan Grant (played by Sam Neill) in the movie Jurassic Park, pronounced Griffen a stegosaurus.

It wasn't a big find in the literal sense--stegosauruses were 26 feet to 30 feet long and about 10 feet tall when full-grown--but scientifically, it was significant. A stegosaurus had never been found this far north. Even in more usual locations (southern Wyoming, Utah, and Colorado), only a half-dozen stego skeletons had ever been found (compared with 28 T. rex specimens).

From the Jurassic Period, 145 million to 210 million years ago, Griffen is twice the age of most dinosaurs found in Montana. He died before reaching maturity, too, a circumstance that makes him even more intriguing to researchers. The Yureks went looking for a museum to help.

Nate Murphy, a self-taught paleontologist and director of the JRDI as an amateur paleontologist in Malta, Montana, says he gets dozens of calls a month from people who think they have found a dinosaur in their back yards.

Murphy's colleague, Australian paleontologist Mark Thompson, took Mrs. Yurek's call. "Nate, this woman thinks she's got a stegosaurus," Thompson said, handing the phone to Murphy and twirling his finger around his ear. "Jack Horner says so," Mrs. …