“Ready: standing draw … now!”Chris yells from the stern, as we slide into the Chute and spin across the eddy fence. Suddenly we are barreling straight down the Class II Roller Coaster section of the Isaac River in his restored cedar-canvas Chestnut canoe. As I watch out for rocks in the transparent, emerald water, my excitement gives way to astonishment at the towering beauty we are slipping through.

Tall cedars and hemlocks lean over us, draped with lichens and moss nourished by the river's spray. Large boulders protrude from the riverbanks, and we glide over a few sunken fragments of old canoes wedged like empty shells in the rocks and gravel. After a short portage around the Class V Cascades, we're back in the river, which now snakes its way toward the 36-foot Isaac Falls. We paddle hard to reach the pullout for the portage around the falls and the logjams that extend upstream from them.

My first trip around the Bowron Lakes Provincial Park in the Cariboo Mountains of central British Columbia is the 100th circuit for my stern partner, Chris Harris, a photographer and former paddling guide. We started the circuit in late May 2000, just after the ice had broken up and the 576-square-mile Provincial Park opened for the season. This designated wilderness area is half the size of Rhode Island, and we felt as if we had it all to ourselves. We sometimes went a whole day without seeing another canoe or kayak. Spring's high water levels increased the power of the rivers, adding to the sense of isolation and adventure.

I have returned many times since that first trip with Chris, completing the 70-mile circuit three times and making a half-dozen shorter forays into the park. Each of these trips has been unique, thanks to the area's physical and natural diversity, and dramatic seasonal fluctuations of daylight hours. Around the summer solstice the sky barely darkens, while in fall the northern lights illuminate the long nights. A series of portages and rivers link the 11 lakes, forming a singular paddling route that passes through four distinct ecosystems and draws 5,000 visitors each year. Though the circuit traces a roughly rectangular route through the Cariboo Mountains of central British Columbia, the journey feels more like a circle, as the unique personality of each lake flows naturally into the next.

Isaac Lake, the east side of the rectangle, defines the circuit for many. It can take two days to paddle this narrow, 23-mile alpine channel. Then five miles of fast water on the Isaac and Cariboo Rivers punctuate the long hours of lake travel. The silt-laden Cariboo changes course each spring, leaving snags and sleepers to dodge, as well as sandbars to picnic on. The entire region teems with wildlife: moose, grizzly and black bears, otters and eagles. Beavers often swim near the Cariboo's mouth, where the scent of cottonwoods floats in the air. Here the mountains open up to reveal Lanezi Lake's turquoise glacial water.

Paddling westward toward Sandy Lake, the landscape widens. The darker tones of the eastern rainforest give way to lighter greens in this milder, drier environment, while occasional patches of red and charcoal mark forests killed by mountain pine beetles or scorched by fire. Families of otters cavort in the current flowing from Lanezi to Sandy Lake. After the intensity of the east side, this section feels laid back, even lazy.

The west side's short, easy portages and lower registration fee entice many people who don't want the challenge of the full circuit. It's always busy in August. In the high season, the adventure and solitude of the east side gives way to anxiety about finding a vacant campsite on Spectacle Lake. The crowds sometimes make me yearn for the quiet seclusion of early and late season trips, but swimming in warm water and lazy paddling are often a welcome change in summer.

I feel the spirit of this Canadian wilderness most acutely in the fall. My most recent trip on the chain was in early October. My friend Jessie came along from nearby Wells, and we started down the west side. Ice was already starting to form on the shallower waters of Swan Lake, and we realized that if we lingered for too many days, we would need an axe to break a path through the ice.

In four days we saw just five other people. The cold and solitude heightened my awareness of risk, as well as beauty: grizzly bear tracks in the sand, poplars glowing gold as morning mist burns off, and fresh snow dusting the peaks.
Before breakfast on our last morning, we walked down to the beach from our tent at Pat's Point on Spectacle Lake to splash our faces. The water rippled silently away from our hands and softened the reflections of sand, trees, and sky. All the normal, nagging details of my daily mind were draining away in this wild, soft place.

Just then we heard a crash, and looked up to see a huge bull moose charge into the lake just 50 feet to our left. As he snorted his way across the narrows, he turned his enormous head to look toward us for one brief moment, then swam across the deepest channel to the far shore, where he rubbed his massive rack against the willows, snorted loudly, and charged into the bush.

Jessie and I stood there staring, wondering if the moose might reappear, but only the dawn's silence returned while the ripples melted into stillness. Humbled by this magnificent animal, we walked back to the campsite. It was time to cook up our oats and load the canoe.

If You Go

Bowron Lake Provincial Park:
You'll pay a reservation fee as well as a circuit fee per person and per canoe or kayak. 800-435-5622, www.env.gov.bc.ca/bcparks/explore/parkpgs/bowron.html

Getting there:
A nine-hour drive north from Vancouver, B.C., or 11 hours from Calgary, Alberta. If you fly or bus to Quesnel or Prince George, you will need to organize transportation to Wells and Bowron Lake from there.

Must see:
Cariboo Falls, where the river drops 78 feet to smash into pre-Cambrian rock. The falls are a half-hour stroll through lodgepole pine forest from Unna Lake.

Although most people prepare themselves for the obvious hazards of the Chute at the mouth of the Isaac River, as well as the Cariboo River, when entering Sandy, Lanezi, and Bowron lakes, large standing waves and strong headwinds can take paddlers by surprise. Bear caches must be used at all sites; moose should be approached with caution, especially those with calves.

The Bowron Lakes: A Guide to Paddling British Columbia's Wilderness Canoe Circuit by Chris Harris, Jim Boyde, and Dean Hull. The small format fits in a Ziploc bag and contains 10 maps of the circuit and 29 diagrams on how to paddle the challenging sections. 800-946-6622, chrisharris.com

Nearby attractions: Eclectic Wells and Barkerville Historic Town, heart of the Cariboo Gold rush. wellsbc.com