Hike to pulsating Heart Lake
Few places bring together Yellowstone's triple feature of wildlife, thermal wonders, and riveting scenics the way Heart Lake does. Grizzlies roam its lodgepole woods (the area's closed until July 1 or later); its waters teem with cutthroat trout. Loons cackle in early morning and evening; expect to spy moose, eagles, cranes, and bighorn sheep. And the nearby Rustic Geyser occasionally spews a 30-foot column of steaming water.
Hike 7.5 miles across rolling terrain from the South Entrance Road trailhead through forest burnt by the '88 fires (read: little shade), now regenerating with wildflowers and saplings. The next day, hike up nearly 3,000 feet in 3.3 miles to Mt. Sheridan's 10,308-foot summit, where the panorama extends south to the Tetons. Reserve a backcountry campsite at (307) 344-2160.
Paddle to boat-access-only geysers
Boating is allowed on three Yellowstone lakes--and just one, Shoshone, sits miles from any road and is motor-free. From a secluded boat-access campsite (reserve in advance), check out Shoshone Geyser Basin at the west end; a 4-mile hiking trail loops past 40 geysers, many of them active. The star is Minute Man, which sporadically erupts in a 40-foot spray. Moose Creek, on the south shore, is a haven for wildlife, antlered and otherwise.
From South Entrance Road, paddle 3 miles across Lewis Lake, then 3 miles up the Lewis River Channel to Shoshone. From there, it's 6.5 miles farther to the geyser basin. Paddle in the mornings to avoid big, choppy water; cross at the half-mile-wide Narrows. At nearly 7,800 feet, the lake is always frigid. www.nps.gov/yell
Day-trip the park's wildlife-rich north
Snow transforms the park's landscape and ushers wildlife--bison, elk, eagles, and often wolves--to the valleys. Scenic cross-country ski tours follow unplowed roads: Try the easy 1.5-mile Upper Terrace Drive loop at Mammoth Hot Springs past the famous limestone terraces (go in early morning for frost-covered trees); the moderate Tower Canyon Road (5 miles round-trip) to Tower Falls and Grand Canyon of the Yellowstone views; and Blacktail Plateau Drive (7 to 8 miles one way), a tougher traverse. Entry-level technique will suffice for the first two trips; the third requires stamina and snow-plow acumen.
To see more in a long weekend--and, well, live large--use the Mammoth Hot Springs resort (www.travelyellowstone.com), a great basecamp for daytrips.