An hour north of Mount Katahdin lies Maine's Aroostook County, the large, sleepy potato-growing capital of the East. Come winter, though, those potato fields turn into a snowmobiler's dream. Connecting to long dormant railroad corridors, densely forested logging roads, and iced-over lakes and rivers, this overwintered region hosts a mind-boggling 2,300 miles of snowmobile trails. Bring a passport and you can cross into the province of New Brunswick, and add another 4,000 miles of trails, half of which flow through state forests and parks.

This two-nation adventure starts in Presque Isle, a town of 10,000 people that serves as the county's economic hub. Stay at the Presque Isle Inn, next door to Kevin Freeman's Sled Shop, where you can rent boards, pants, jackets, helmets, and panniers. Freeman, a former professional snowmobile racer, has logged more than 250,000 miles on snowmobiles in the region, and is also an able guide to hire (unless you want to go it alone, in which case he will send you off with a detailed map).

Go directly across Main Street from the Sled Shop and then head west on the Interconnecting Trail System (ITS) 85. The signage is excellent and routes are well maintained by more than 40 dedicated snowmobile clubs in the area. If you happen to hit a trail just after it's been groomed, you'll feel as though you're driving a Mercedes on the autobahn.

On a 250-mile weekend jaunt, travel west to Portage Lake and have lunch at Dean's, a favorite snowmobile stop known for its fish and lobster stews. Don't miss ITS 105, leading northeast from Washburn to Stockholm, a narrow and level railroad corridor where you can easily reach speeds of 75 miles per hour. Go too fast, however, and you'll miss the moose, deer, snowy owls, and the rare white ermine that call this forest home.

At Hamplin, Maine, you can go through customs on your snowmobile on the way to Grand Falls, New Brunswick, which hosts a long suspension bridge that glides above the St. John River. Make your way to the New Brunswick interior on logging roads and railroad beds where snowed-over balsams stand like spectators at a marathon. The French village of Saint-Quentin is a good place to grab lunch and gas up before making the return trek back across the border to Presque Isle.

More information: PenAir flies direct from Boston to Presque Isle, Maine. Cost of snowmobile rental is $200 a day.

Author of 'Outside Magazine's Adventure Guide to New England,' Boston-based Steve Jermanok blogs daily at ActiveTravels.com.