Sporting a felt hat, a plaid shirt, and a graying beard, Kevin Slater sits in the back of his canoe, looking as comfortable as men his age do while reclining in a La-Z-Boy. His stroke is short, fluid, with an inward snap at the end to steer him exactly where he needs to be in a river dotted with boulders. In front of him sits his peach-colored companion, a husky named Cara. Several months from now, when the maples are barren and the pines heavy with snow, Cara will join a raucous team of Yukon brethren to pull a dogsled through the melt. But with the maples and poplars on the hillside radiant with splashes of yellow, plum, and purple, Cara can rest, her head jutting out over the gunwale.

Like the paddles my companions and I grip in our hands, the wood-and-canvas canoes we ride in were crafted by Slater. It takes more than 120 hours of work to carve one of these delicately ribbed beauties out of northern white cedar and cherry. Slater uses only native varieties.

From left: Slater and Cara take a break while paddling the West Branch; carbo-loading on potato pancakes for breakfast; guides Sue Szwed, left, and Shannon LeRoy prepare lunch along the Penobscot; Szwed at the helm.

"I was taught that you can find anything you need to make in these woods," Slater says. He learned his skills from a mentor he refers to simply as the "Old-Timer." As in, "After paddling the entire Allagash together, the Old-Timer told me to go to the local store and get 10 days of supplies. I was going to go back upstream on my own. That's how I learned how to canoe these rivers." Slater is the latest in a long line of teachers and students who have learned to live in Maine's North Woods and to navigate its maze of blue waterways--a seemingly countless number of lakes, streams, rivers, and ponds that branch off in every direction to form this capillary system deep in the forest. The baton (or in this case, the paddle) has been passed from the Wabanaki Indians to European fur traders, to naturalists with names like Emerson and Thoreau, to the timbermen of the 20th century, and now to recreational paddlers like you and me who yearn to get lost in a timeless bubble far from the hyperkinetic mind-set of PDAs and URLs.

For the next four days, Slater, co-owner of Mahoosuc Guide Service and president of the preservation-oriented Maine Wilderness Guide Organization, will lead five paddlers up the 40 miles of the West Branch of the Penobscot River, a rite of passage for generation after generation of New England paddlers. Henry David Thoreau paddled this river twice, in 1853 and 1857, led by his trusty guide Joe Polis, whom he referred to as "Indian Joe" because of his Penobscot Indian lineage. Were it not for Thoreau's good friend Horace Greeley, who published Thoreau's poignant observations posthumously in an 1864 book simply titled The Maine Woods, some of the earliest American musings on conservation would have been lost. Thoreau came to the Maine interior, far away from the manicured farmland that consumed most of the region at the time, yearning to be lost in a dense wilderness. "The country is virtually unmapped and unexplored, and there still waves the virgin forest of the New World," he wrote.

From left: LeRoy teaches the author fly-casting; The crew head to the church in the center of Chesuncook Village, until recently accessible only by boat or float plane; Szwed fetches water at Sandy Point.

Like most Americans today who make the trek this far north, Thoreau was particularly excited to see moose, which he likened to "great frightened rabbits, with their long ears and half-inquisitive half-frightened looks." Of course, maybe that's because his guides were about to hunt the moose down. The one moose I'd spotted within moments of loading our canoes at the confluence of Lobster Stream and the West Branch had seemed uninterested in us as she'd dipped her long schnoz into the water and started to slurp. Her two young calves, however, had run headlong into the brush.

Sitting in the bow of Alan Stearns's canoe, I watch as he eyes a ripple in the water 100 yards ahead and easily glides us through a hidden bed of submerged rock. The river has a slight current, and the water is a tad green--the same color as the tall spruce in this northern boreal forest. Stearns, the deputy director of Maine's Bureau of Parks and Lands, last paddled the Penobscot as a boy, on a trip with his parents, founders of the popular Penobscot Paddle and Chowder Society in nearby Bangor. In 1974, Stearns's mom and dad guided a group on a fact-finding mission to see whether the Penobscot River could join the Allagash Wilderness Waterway and become part of the National Wild and Scenic Rivers System. Ultimately, it did not make the cut, but it is still protected on either side by a 500-foot easement established by the state in 1981.

Slater thinks the easement is far too small of a conservation effort. "We protect 200-year-old buildings in Maine as historical sites but not these paddling routes that go back at least 5,000 years," he says.

The easement was originally granted to Maine by the Great Northern Paper Company, and today the land is owned by a consortium of timber companies. Timber remains king in this part of the United States, as I learned during an hour-long drive on rutted-out dirt roads from Greenville, a small community on the southern end of 40-mile-long Moosehead Lake that's considered the gateway to Maine's North Woods. Logging trucks speed down the road with their fresh-cut cargo, and travelers must register at a gatehouse and pay a daily fee to the partnership of private landholders who own these 3.5 million acres.

It wasn't until after Thoreau died that lumbering became big business here. Felled logs once clogged the Penobscot for miles as they floated to the mills. Watching the first loggers move into the woods, Thoreau was prescient enough to anticipate what would happen over the next century. In The Maine Woods he wrote, "Pine is no more lumber than man is, and to be made into boards and houses is no more its true and highest use than the truest use of a man is to be cut down and made into manure."

The towering white pines are long gone, used mainly for masts on British warships, and the fir and spruce have been clearcut repeatedly over the decades, resulting in a scragglier forest of softwoods and hardwoods. But ever so slowly, these "beauty strips," as environmentalists call them, are starting to regain some of that raw, unkempt look that attracted Thoreau and his Concord, Massachusetts friends. The air is scented with sweet pine, and the sky filled with herons, ospreys, and eagles.

We awake the next morning to a forest wet and gleaming with the residue of the night's rain. Slater has the coffee heating over a roaring fire. Shannon LeRoy, former owner of Medawisla, one of the few remaining sporting camps in these parts, and Sue Szwed, a longtime guide who tends her apple orchards and organic gardens when she's not plying the rivers, are busy whipping up pancakes with blueberries from Szwed's farm. To my delight, I learn that the food on this trip is not freeze-dried. We dine on salmon caught on the fly by LeRoy and mushrooms foraged by Szwed--ingredients that an urban restaurant would spend heftily to put on its menu. Muffins and peach cobbler are baked in a reflector oven nestled next to the flames.

Over the course of our trip, we see the Penobscot transform from a narrow, winding stream, shallow and bony in parts, to a deep, wide river near Chesuncook Lake. When the currents create a rip around Big Island, Szwed stands up and grabs the setting pole. Steady at the helm, she guides us around the bed of rock, jabbing to turn the canoe swiftly or to stop on a dime. Every so often we come upon a reminder of the lumber drive, like the boom rings jutting out of rocks where chains once held back rafts of logs. At one point, we go ashore to inspect the battered remains of a century-old flat-bottomed bateau used to herd floating logs.

"I love poking around and finding remnants of those who went before us," Slater says, sounding like an old-timer himself. The conversation turns to carving your own canoe, and LeRoy chimes in that her friend has just finished building a birch-bark canoe. Slater's eyes light up, and the normally demure guide becomes animated, knowing full well the history of the birch-bark canoe. When English explorers arrived on the Maine coast in the early 1600s, they were approached by Penobscot Indians who could paddle their canoes faster than eight men rowing a boat. Trappers and woodsmen quickly embraced the Native American mode of transport, but by the late 1800s, it was becoming harder and harder to find a birch big enough to shape a canoe out of. That's when wood and canvas canoes surged in popularity. The form remains essentially the same, and so does the backbreaking work of bending ribs, attaching planks, and stretching canvas over the hull.

As we approach the moss-covered rocky ledges of Fox Hole, LeRoy leads us to shore so she can break out her fly rod and try to hook a salmon on the last day of the season. Though there's no luck on that front, we do manage to spot a rare white-winged crossbill (whose beak is in fact crossed) playing in the mud. After lunch we take a detour off the Penobscot at Pine Stream to find a forest that hasn't been harvested for decades. Black spruce tower over the dense underbrush, evoking what it might have looked like during Thoreau's time. When we turn around, we spot a chubby black bear swimming across the river and quickly paddle toward it to get a closer look as it runs ashore.

The next morning, a laughing loon echoes across the waters of the Penobscot as we finally leave the river and enter 22-mile-long Chesuncook Lake. This is a major thoroughfare for paddlers in the Maine woods, with waterways branching off like the spokes of a wheel. The Northern Forest Canoe Trail heads north to Umbazooksus Stream, encompassing the challenging 2-mile-long Mud Pond Carry and eventually reaching the Allagash. We head southwest along the lake's shore to get a better view of mighty Mt. Katahdin, whose broad shoulders and 5,267-foot head are shrouded in a low-lying cloud.

One of the last remaining white pines guards the entranceway to Chesuncook Village, which, until a recent timber road was built, could only be reached via canoe or float plane. Thoreau ventured here for one night in 1853, "to see how a pioneer lived." He dined on moose meat and applesauce and slept in a primitive log cabin. We stopped to visit the church, built a half century after Thoreau's visit, and to grab a bottle of homemade root beer from the porch of Jack Murphy, one of the village's eight residents. Murphy makes his living as a gunsmith, fixing firearms that people send to him from around the world.

At the end of his Chesuncook chapter in The Maine Woods, Thoreau asked this then-novel question about the northern forests and the web of waterways they envelop: Should they be preserved "for inspiration and our own true recreation, or shall we like villains, grub them all up, poaching on our own national domain?" Land use remains a contentious issue in Maine, with large timber companies transforming into real estate developers. Plum Creek Timber Company was recently given the right to build 975 houses and two resorts on the shores of Moosehead Lake in exchange for donating 400,000 acres to the Appalachian Mountain Club and the Nature Conservancy. (The decision is being appealed by the National Resources Council of Maine. In a note mocking Plum Creek's generosity, the Sierra Club's Maine Chapter decried "a parade of forest fragmentation and development across this last large natural landscape of the east.")

Stearns tries to put a bright spin on the contentiousness. "Ever since I was born," he says, "you put your right-wing fanatics and your left-wing fanatics in a river like the Penobscot and they have no quarrels. Everyone's just happy playing in the water." Slater counters with a more cautionary message: "I hope people are guiding in the Maine bush 100 years from now, 500 years from now."

Slater tells me to climb into the stern of his canoe as we make a final push along the shores of Chesuncook. Rarely does a guide give up the coveted backseat of a canoe, preferring to be in control of the navigation (and pretty much everything else). But Slater has learned from the Old-Timer and understands that to be a master of one's destiny also means passing on knowledge to the next generation. I do my best to steer the canoe in a straight line, despite a steady headwind, while Slater gives me pointers on the best stroke to use. Eventually, we reach a sandy campground opposite Katahdin. The clouds that have hidden the peak for days start to peel away, and in their place is a rainbow. Cara, the husky, finds a soft spot on the beach to lie down and take in the spectacle. Actually, to fall asleep. Tired from a full day outdoors, I quickly follow her cue.