CHIMNEY POND, ME
Climb to a frozen cirque
This trek's payoff is huge, literally: Katahdin's couloirs and 300 feet of draping ice known as the Pamola Cliffs. This 30-mile round-trip to Chimney Pond is an epic weekend for winter-ready hikers. Start at Abol Bridge in Baxter State Park and head east on an unplowed park road past Abol Pond's frozen, moose-tracked wetlands. Turn north at Togue Pond gate for an eight-mile uphill to Roaring Brook Campground's wood-heated bunkhouse. Day two: Climb 3.3 miles and 1,500 feet past gumdrop-shaped boulders in Roaring Brook. The trail tops two moraine hills before treeline, then reaches the entrance to the South Basin's glacial cirque and the sensational Pamola Cliffs. (207) 723-5140; baxterstateparkauthority.com
Thaw out with the Appalachian Trail Café's legendary Millinocket Special, a $5 pile of home fries, eggs, and cheddar cheese. (207) 723-6720; appalachiantraillodge.com
From Bangor, head 59 miles north on I-95 to Millinocket. Follow ME 157 11.5 miles to Katahdin Ave. and turn right. Continue 18.2 miles toward Abol Bridge.
CHIPPEWA MORAINE, WI
Snowshoe to a glacial retreat
Head to the rolling hills of the Chippewa Moraine, a pond-studded slice of Wisconsin's glacially carved northwest corner. From the Chippewa Moraine Interpretive Center, take the Ice Age Trail one mile to a debris field left behind by a mile-thick sheet of ice. In the next five miles, you'll skirt 20 frozen kettle lakes and glacial erratics–five- to six-foot tall boulders left behind by a retreating glacier. The path heads east and hugs the wild shorelines of Knickerbocker and Horseshoe Lakes, tracking small ridgelines. Find open camping along the trail west of Dumke Lake; look for ridge-shielded sites on the south side of the path. (800) 227-0046; iceagetrail.org
Winter camping too chilly? Arrange a pick-up with Jacks Lake B&B. After a warm snooze and hot breakfast, get a lift back to the trail. (715) 967-2593; jackslakebandb.com
From New Auburn (125 miles northwest of Minneapolis), head .7 mile east on Main St. to a left on N East St. In 0.5 mile, go left on CH M, which leads to the trail.
LAVA BEDS, CA
Descend into an Ice Cave
December temperatures can swing into the high 60s at Lava Beds National Monument. But 100 feet below the cinder-covered surface, in the Crystal Ice Cave, it's below 32°F year-round–prime conditions for ornate ice formations. You'll need a helmet, headlamp, gloves, and kneepads for this four-hour, quarter-mile scoot-and-shimmy past enormous ice columns, rounded stalactites, and an awe-inspiring 20-foot-tall crystal curtain. Afterward, pitch a tent at the lava-covered Indian Well campground north of the visitor center. The next day, squeeze in trips to three other frozen caves: Skull, Heppe, and Merrill (the latter once housed a skating rink). Make reservations three weeks in advance. (530) 667-8113; nps.gov/labe
Soak in the steamy waters of Stewart Mineral Springs. (530) 938-2222; stewartmineralsprings.com
From Redding, drive 70 miles north on I-5 to US 97. Drive 54 miles north to CA 161. Turn right, drive 17 miles to Hill Road, and turn right again; follow signs for the monument's visitor center.