Three weeks, 21 teens, 13 canoes and more than 150 miles of Missouri River -- just what would that take? Four dedicated teachers with undaunted enthusiasm and a passion for Lewis and Clark.

The group of Fairfield, Conn., high school students shoved off for home Tuesday after what they said was the adventure of a lifetime, tracking the path of Lewis and Clark through Montana.

The students paddled the wild and scenic stretches of the Missouri, visited the Blackfoot Indian Reservation, fleshed and tanned hides, climbed mountains, cooked for themselves and bonded as a team.

"I had no idea what I was getting into," said student Phil MacDonald. "It turned out to be so much bigger than I thought it would be."

Several students had never camped before, and most had never seen Montana's diverse wildlife. They bubbled with stories of bighorn sheep and mountain goat sighting and close encounters with rattlesnakes.

"I saw elk for the first time, and buffalo -- I've never seen an animal that big in my life," said Nick Walket

Throughout the trip, the students were charged with writing daily journal entries -- just as was done by Lewis and Clark and members of their party. The task proved difficult.

"It was really hard to keep up and it was hard to take time and catch up," said Patrick Keane.

"Even if we did have time we were too tired, so we'd just end up putting it off another day," MacDonald added.

Hosted by the Montana Science Institute, the expedition was part of a summer school program launched by teachers Chris Parisi and David Nulf, who teach a block class combining history and English.

"Like a lot of people we read Stephen Ambrose' 'Undaunted Courage,' " said Nulf. "That just grabbed us on a deep level."

That was almost four years ago, and since then, the duo has been planning a Lewis and Clark trip for their students. They started dreaming, then brainstorming and finally called Gil and Marilynn Alexander at the Montana Science Institute. Initially, Parisi and Nulf came out to the institute for a Lewis and Clark course geared toward educators.

That was two years ago, and they left knowing they'd be back with their students.

Students were chosen based on an application process, and raised over $50,000 with auctions, car washes, raffles and selling doughnuts at school to fund the trip.

The Alexanders made arrangements for the expedition, organizing every detail, and provided the accommodations at the institute when the youngsters weren't camping out.

"We really needed help on the ground out here, not knowing Montana at all," said Nulf. "If we would have had to go through professional outfitters, we wouldn't have been able to afford it."

In all, the students' schedule was packed with in-the-field learning experiences they couldn't have gotten from the classroom, Parisi said.

"They covered more of Montana than most Montanans get to," said Gil Alexander.

And that included a six mile up-stream venture on the Jefferson River, towing their gear in canoes against the current in the same way Lewis and Clark made the first leg of their journey up the Missouri.

"That's an experience you absolutely don't want to do again," Parisi said. "But just floating with the current wouldn't have been representative of Lewis and Clark."

Reporter Laura Tode can be reached at 447-4081 or by e-mail at laura.tode@helenair.com.