> WHY TO GO: A strong current zips us past a lush British Columbian forest and the chalky walls of a low canyon. Our Canadian Rockies Whitewater guidebook says that easy paddling will be interrupted by rapids up to Class III. Maybe that’s true at higher flows, but on this late-August afternoon, boulders and Class II riffles are keeping us sharp with boat scouting. Waves from the tricky Horseshoe Rapid-the run’s most challenging boulder garden-bounce into our boat, turning it into a floating icebox.

Here in Kootenay National Park is the Canadian Rockies’ crown of canoeing rivers: the upper Kootenay (Koot-in-ee). The canyons pulse in and out like an ebbing and flowing tide. At times, the walls are the height of a paddle, but now the river digs a few hundred feet into the water-soluble limestone bedrock. That’s what turns the water lagoon-blue; it’s also turning this into a magical vertical world. Rounding a sinuous S-bend, we encounter a spectacular waterfall where Pedley Creek cascades into the deep gorge onto a riverside shelf. We climb out to get a refreshing shower. We’re completely alone because the only way to get here is by canoe.

> IF YOU GO: The entry fee is $16 per family/group to visit Kootenay National Park. Once the river exits the park, it flows through provincial land that doesn’t require any permits or fees. Though it feels remote, forestry roads follow nearby on river left. You’ll find plenty of excellent wilderness campsites along the route that do not require a permit. The fishing is very good, so pack a rod and buy a B.C. provincial fishing permit. Canadian Rockies Whitewater (South Edition), by Stuart Smith (Headwaters Press), has a detailed description of the shorter “inner” run. Buy topographic Maps 82J12 and 82J05 and rent gear at Calgary’s Mountain Equipment Co-op (www.mec.ca). Or, for a guided experience, Nahanni Wilderness Adventures (www.nahanniwild.com) offers a five-day trip. Check out www.kootenayrockies.com for a guide to local accommodations and activities. Oh, and you’re in bear country, so don’t forget your spray.

> WHILE YOU’RE THERE: On the Kootenay, stop and hike 1.5 miles up the Cross River into a magnificent cascading canyon to a natural-rock bridge. Off the river, soak in the nearby hot springs. Try Radium Hot Springs, within the national park, or the luxurious warmth of Fairmont Hot Springs, near Canal Flats. Whiteswan Hot Springs are only a 15-minute drive from the take-out. Ask locals for directions.

Put-In: McLeod Meadows Campground in Kootenay National Park
Take-Out: The village of Canal Flats
Miles of Paddling: 64 miles. The trip can be made shorter by access points on forestry roads.
When to Go: July and August offer most reasonable flows and best weather.
Best Boat: Canoe or inflatable craft
Local Shops: Calgary has three great paddle shops: Aquabatics, Undercurrents, and Mountain Equipment Co-op.
Fast Fact: Along with other Rocky Mountain National Parks, Kootenay National Park is a UNESCO World Heritage site.