As I speed through the curves and over the hills of a trail that runs through a tall forest of pines and birch, it occurs to me that I rarely think of biking as something to do in the North Woods.

At every bridge that crosses a marshy creek, or lakeshore view of sky-blue, I feel a jolt of surprise and think I should be paddling a canoe rather than pedaling a bike. That comes, I suppose, from going to a cabin most of my life and doing all that backwoods stuff: fishing, boating, canoeing, hunting. In the wild lake country of north-central Minnesota, biking always seemed too civilized.

Shows what I know. In fact, there are hundreds of miles of bike routes and trails through northern Minnesota's conifer country, as several friends and I discovered on a weekend in Walker, riding the Heartland and Paul Bunyan state trails.

The Heartland is one of Minnesota's oldest rail-to-trail projects, running 49 miles from Cass Lake south and west to Park Rapids (with plans to reach as far west as Moorhead). The Paul Bunyan follows the old Burlington Northern route from Brainerd about 112 miles to Bemidji, the longest continuously paved trail in the state. Both trails are popular with inline skaters and hikers, and are smooth enough for wheelchairs. But by far the most popular use is biking.

We had been looking for a north-country bike route when we noticed an intriguing possibility. The two trails cross, forming a big "X" centered right on Walker, on the shores of Leech Lake. We figured that with a bit of creative freelancing on county roads, we could turn the X into a Figure 8. We could start in Walker, bike a full day, return to Walker, and bike another full day.

We set out from Walker on a sunny Saturday morning in early September, the colors in the roadside grasses and forest hinting strongly of autumn. We caught a spur that runs through the heart of downtown and soon reached the main trail. (Actually, the Heartland and Paul Bunyan join and run as one for a couple of miles near town.)

The trail was smooth, and, because it's an old rail bed, absolutely level. Passing other cyclists out for their morning exercise, we sped past waving grasses, late-blooming asters, yellowing birch, and plush heads of sumac. To the left, a line of trees and a berm of high ground screened the trail from nearby Hwy. 371. At a bridge over the channel between Kabekona Bay and Walker Bay, we stopped to look in the clear water. Near Steamboat Bay, the trail, though still marked, shunts into a country road for about three miles and then back onto the rail grade.

Soon we came to County Road 66, and turned west to catch the Paul Bunyan Trail, the other leg of our X, 10 miles to the west. According to the state Department of Transportation map, at least what I could understand of it, the road was paved and had little traffic.

Hello, gravel

After a couple of miles the blacktop abruptly ended and we bumped along on gravel. Luckily, we all had mountain bikes or hybrids. Nonetheless, it was a lovely day for a bike ride at the speed of a quick walk.

"I'm surprised," said Lee-Hoon Benson, who tried to remain chipper despite some annoyance with the gravel. "There aren't very many people at all."

"Not going the way we went," quipped another of our group, who shall remain nameless.

But soon we come again to pavement, sped along the shore of Garfield Lake and hit the juncture with the Paul Bunyan Trail. After a short break, we pedaled through tiny Laporte and back toward Walker, the welcoming expanse of Kabekona Bay on our left, and the radiant late summer afternoon sun on our right, shining through fir and birch.

Our lodgings were the City Dock Cottages. We had an open cabin with 10 beds upstairs and down, and pine paneling throughout, siting directly on the waterfront and just two blocks from the bike trail.

Any town is improved by a big body of water at its doorstep, and Walker is no exception. Leech Lake is famous not for bike riding, of course, but for walleye, big muskies and other fish. As we sipped beer on the porch, owner Jerry Stewart stopped by. He'd been on the waterfront since 1960, and now splits his time between Walker in the summers and Pine Island, Fla., in winter. He recalled more than 30 years ago, when he owned a trophy shop in town. City leaders stopped by one day to ask if he would fashion a trophy for something called an Eelpout Festival.

"A what?" he asked of the now famous fishing extravaganza held each winter.

We'd landed there in the midst of Walker's Ethnic Fest, which was surprising, given the homogeneous demographics of most small northern Minnesota towns. We walked up 5th Street past tables of wind chimes, yarn work, dreamcatchers, woolen mittens and other crafts. On Minnesota Avenue, we found three live bands. The most compelling, by far, played reggae, a cultural link I hadn't anticipated in northern Minnesota.

On the other hand, dinner was perfectly native -- beer and pizza at Benson's Eating and Drinking Emporium.

Southbound

After breakfast, we headed out on the trail, this time turning south on the Heartland. Again, we found a smooth path through northern pines and hardwoods. I was tempted to pedal into Akeley to see the Paul Bunyan Historical Museum. (Is it possible to devote a "historical museum" to a fictional character?) Instead, we turned off on the junction with the Paul Bunyan Trail, the last leg of our big X.

The next 6 miles departed the straight, flat rail bed and instead followed the hilly contours of the glacial hills. We were delightfully surprised by hills and curves. We sped down the slopes and pumped hard uphill past big pines, trees that have matured in the century since Paul Bunyan cut the forests down.

"That was one of the best bike rides I've ever done," exclaimed Karen Lucas, a bit breathlessly from the ups and downs. "Keeps your interest, has lots of variety, never know what's around the corner."

It was a thrill. Our ride back to Walker along the still-incomplete Shingobee Trail was a disappointment: We had to ride the shoulder of busy Hwy. 371 part of the way (not a route I would do with children). Still, biking in the North Woods had been a delightful surprise.

Greg Breining writes about science, nature and travel. His most recent book is "Paddle North: Canoeing the Boundary Waters-Quetico Wilderness."