All you can say is "Wow," "No way," or "Holy cow." You could say other things, too, seeing Katie Scott up against some of the biggest rapids on the planet.

At only 20, Scott is already considered one of the top female kayakers in the world. Now, come next week, she'll travel the planet documenting three endangered rivers while dipping her paddle into some of the most unforgiving water known to man.

Scott, from Helena, will leave for Nepal to begin her journey with a group of kayakers to make a documentary already dubbed "The Final Descent."

Likely to take a year to shoot and edit, the film will someday play at universities around the country, not to mention a little thing known as the Banff Mountain Film Festival.

"We just came up with this idea," she said. "We wrote the proposal and I called 30 different companies to meet with them. I went to the outdoor retail show in Salt Lake and since August, it's been about following up."

Scott described the documentary's purpose - to bring attention to some of the world's most beautiful and ecologically significant rivers, each threatened by large-scale hydropower dams.

During the trip, Scott will help produce the whitewater adventure film. She'll descend the rivers on the trip of a lifetime, documenting the free and wild waterways for what may be the final time.

"It will definitely be a whitewater kayaking film," she said. "But it's going to focus on river conservation and the effects the dams will have on local populations. We're going to document the areas and interview the people on how the dams will change their life, for better or for worse."

Next week, Scott will leave for Nepal to paddle the Marsyandi River, which flows from the Annapurna range in the Himalayas. While the river is considered among Nepal's most spectacular, its future is threatened by a large dam already under construction.

Scott said the hydro project will flood part of the canyon above the dam and de-water the stretch below it. That, she added, would effectively destroy the ecology of the river system, the whitewater, and the traditional way of life for the people who live along the river.

"It'll be me and my best friends in the gorge on this river, the most beautiful place you can imagine," she said. "I totally want to expose these areas so people can realize the value of this natural resource and beauty."

Following the Marsyandi trip, the team will travel to India to paddle the Brahmaputra River. With its big rapids and rugged terrain, the river is considered one of the most inaccessible in the world.

The trip will take seven days to complete and be totally self-contained. The rapids, Scott noted, are said to be twice as big as those in the Grand Canyon.

"The Brahmaputra flows from China into India," she said. "That's going to be amazing whitewater, but it will be interesting to film. China is building the dam, but India will lose a huge source of water because of it."

The final leg of the expedition will take Scott to Africa - Uganda more precisely. There, she'll attempt the White Nile River, home to some of the largest rapids on the planet.

Scott said the World Bank is funding a 200-megawatt dam near the outlet of Lake Victoria. The lake is one of the largest tropical lakes in the world. The project, some say, could alter its delicate balance.

What's more, Scott said, the project will likely flood the rapids, along with the homes of nearly 7,000 people. Scott said the local population draws both spiritual and cultural pleasure from the rapids, which could disappear next spring as the project moves forward.

"Our project has interested so many people," she said. "The companies sponsoring us are really into outdoors and athletes, but they're also into environmental conservation. It's why the video appeals to a lot of people. It's going to have a lot of class five whitewater."

Born from a water-crazy family, Scott began kayaking at age 12. She left Helena to attend the World Class Kayaking Academy, graduating in 2005. She jumped feet-first into the sport, tackling the Alberton Gorge and its class three rapids on the Clark Fork River.

"You keep building your experience - keep building your confidence," she said. "The more you learn about water, the more you learn about how to react."

Tough whitewater is nothing new to Scott, who's made fast moves forward in the sport she's come to love. She helped found Ebb and Flow Productions and talks fondly of past trips to Chile, Ecuador, Costa Rica, Argentina and California, where "creeking," as she called it, has become increasingly popular.

"It was actually a run we had to hike in 12 miles to get to with a heavy kayak full of sleeping bags and food," she said, recalling one recent California outing down Cherry Creek. "That was one of the runs I'd seen in a video a long time ago. I was thinking I'd never do that."

Shrugging off the apprehensions that come with passing the point of no return, Scott completed a series of paddle strokes above Cherry Bomb Falls on Cherry Creek and went with the flow.

"That's the drop into the first gorge - the most dangerous drop on the river," she said, referring to a crazy picture of her going down the waterfall. "You're just surrounded by these giant granite walls. Once you take your first paddle stroke on a drop, you just stop thinking. It all kind of happens. You think above the drop, but once you go over, you just go with it."

Reporter Martin Kidston: mkidston@helenair.com or 447-4086