BOISE, Idaho (AP) - For 15 summers, Steve Russell has scrambled along the same forest deadfall and rocky hillsides that Meriwether Lewis and William Clark's Corps of Discovery encountered in Idaho's mountains two centuries ago.
The route Lewis and Clark took is largely untouched. It is the same route that the Nez Perce Indian tribe under Chief Joseph used to escape the U.S. Cavalry in 1877. The Nez Perce were Samaritans to the Lewis and Clark group, providing it food and shelter.
But instead of a flintlock rifle and trade beads, Russell carries state-of-the-art mapping equipment to pinpoint within several feet the actual ground the expedition crossed as it made its way west over the treacherous Bitterroot Mountains in 1805.
The Lolo Trail, as the explorers' route is called, "spans a land of history, exploration, courage and danger," said Russell, a professor of electrical engineering at Iowa State University. "It is regrettable that we will never be able to fully learn about its early history, but we must learn all we can through our research as well as our firsthand experience while traveling the trail."
While some researchers comb other segments of the explorers' 3,700-mile odyssey, Russell is concentrating on the 130 miles from Dillon, Mont., to the flatland northeast of Lewiston, where the expedition's dugout canoe trip began down the Clearwater River.
Russell wants to preserve the worn path as a reminder not only of the American adventurers but also of the ancient land bridge used by tribes, and later miners seeking their fortunes.
"It's replete with history," he said. "People I talk to say it is the biggest national treasure for trails. It far exceeded the California Trail, the Nachez Trace, the Mormon Trail. We have it virtually intact."
His findings are being recorded for a book he will call "Lewis and Clark - Between the Rivers." Russell also has plans to conduct summer workshops on the trail - much like the ones he has conducted in the past - for educators and history buffs like himself.
"I think it's easier to find the expedition's route in the mountains than the river," Russell said. "The river course has changed so much. The mountainscape doesn't change."
Mapping the trail has consumed Russell, a native of Lewiston. He initially wanted to produce an accurate map for Montana's 1990 celebration of the 100th anniversary of the expedition, but finding the trail and its campsites captured his interest.
Russell, who worked with the initial design team on ground equipment to interpret information from the satellite-based Global Positioning System, uses journals and crude maps, modern topographical charts and GPS technology to map the trail.
But Clark's expedition journal is the foundation for Russell's work. It notes the time of day the party set out each day and camped for the evening. The steeper and more tangled the day's hike, the less territory the expedition crossed. Even the estimated speed of their horses is factored into Russell's equations.
"I put the expedition in an ordered time sequence, produced candidate routes, then did field studies," he said. "It was surprising how many times I was right."
Russell said Clark's maps "are really quite good for the technology and the time he had to do them. But they contain a lot of distortion. When going through good traveling terrain in the Bitterroot Valley, it is quite accurate. When he gets into the mountains and lot of brush, he's overreporting the distance quite a bit."
The GPS system helps him plot the trail, much of which he found eroded and hidden by brush and dead trees.
Some locations had been favored tribal camping spots for centuries, offering grazing pastures and water for horses. "I call them anchor points, they're so well-defined. You can use them as reference points along the way," Russell said.
One important camping spot was the present-day community of Kamiah, (pronounced KAH-me-i) although a lumber yard covers that spot today.
"I've found no artifacts. There's not the usual beer cans left by modern campers," Russell said. "My opinion is there's no difference between how Lewis and Clark might camp and how the Nez Perce camped. The majority of the clues are just finding charcoal from their campfires and other things you can't use to distinguish between the two."
As Idaho inches toward a 2005 commemoration of the bicentennial of the Lewis and Clark expedition, the explorers' story is still riveting.
They crested Lolo Pass in September 1805, then descended along the dividing ridge between the North and Middle Forks of the Clearwater River until they reached the Weippe Prairie northeast of Lewiston. The party underwent a dozen days of misery, struggling through a blizzard and watching their horses tumble off cliffs. They would even resort to eating colts to survive.
"They weren't used to mountains like this," said Larry Jones, an Idaho state historian.
In 1998, Russell hiked the Idaho leg "in all kinds of weather, walked in rain and snow. I wanted to add to my perception of what they accomplished," he said.
Some people suggested he ride a horse to get a feel for the Corps' progress when they had mounts. But Russell said that would be difficult and "just too dangerous for horses.
"The trail in its present state is only good for those with expert horsemanship and a horse with a lot of bushwhacking experience."
Suzi Neitzel, deputy state historic preservation officer, said Russell has come closer than anyone in mapping the trail. His information, she said, will help the U.S. Forest Service determine how to preserve it.
Bruce Reichert, who produced a special "Lewis and Clark in Idaho: Echoes of a Bitter Crossing" for Idaho Public Television also has nothing but praise for Russell's doggedness.
"He's a godsend to those people who want to find and preserve the trail," Reichert said. "He's very committed to leaving the trail as it is."
On the Net:
Lewis and Clark Trail Heritage Foundation: www.lewisandclark.org/pages/story0.htm or www.lewisandclarktrail.com