POINT REYES, CA
El Nino killed 85% of Point Reyes' elephant seal pups by sweeping them into the open Pacific before they learned to swim. But the population has rebounded; to see clusters of pups, hike 1.2 round-trip miles on McClure's Beach Trail, which descends through a ravine and out onto the wave-bashed coastline.
Bighorn sheep traipse through the national park in herds, babies in tow in spring. Traverse one of the high-altitude loops around 6,646-foot Logan Pass (the 4.5-mile Piegan Pass and 4.7-mile Siyeh Pass Trails are good bets) to see the lambs learn the ropes on vertiginous terrain.
MOOSEHEAD Lake, ME
The moose is Maine's state animal, so Moosehead is as likely a place as any to yield calf sightings. Climb 2,200 feet up Barren Mountain on a remote 8-mile out-and-back stretch of the Appalachian Trail; if you don't see the big mammals' velvety progeny along the way, your chances improve atop the rocky, exposed 3,681-foot Barren Ledges.
Hike the Long Pine Key Nature Trail's 7 flat miles to Pine Glades Lake to see baby alligators--but stay at least 20 feet away to avoid aggravating their mothers. On the way past pine forests, hammocks and finger glades, watch for the Glades' other species: the wood stork, the tiny green anole lizard, and the roseate spoonbill.
ALGONQUIN PARK, ON
Gray wolves are famously shy around humans, so you'll need a little luck on the 21-mile loop of this Canadian park's Western Uplands Backpacking Trail, which runs through old hardwood forests and skirts tons of lakes. Try your own howl at one of the waterfront campsites; we've had packs respond to our amateur calls (listen carefully for the immature yips of young pups).
CRATER LAKE, OR
The 33 Pacific Crest Trail miles that pass through the volcanic national park promise glimpses of the northern harrier (a.k.a. marsh hawk) during spring nesting season. The predators are one of the only hawk species to nest on the ground, making it more likely that you could spy a chick. Until 1995, this section of the PCT didn't afford a view of the lake; now, an offshoot takes you to the rim.
Forget watching bison from a car in Yellowstone. Chart your own backcountry path to watch the big mammals and their fuzzy, orangey calves on the grassland prairie of 64,250-acre Sage Creek Wilderness, in the national park's northern quadrant. You can watch from a safe distance--and never have RVers piling on.
WILLMORE Wilderness PARK, AB
Much less frequently traveled than neighboring Jasper, Willmore has 469 miles of trails through valleys frequented by woodland caribou and their 13-pound, spindly-legged fawns. Head cross-country to open ridges in the Eagle's Nest Pass region and around Persimmon Basin.
TONGASS NF, AK
Kayak 30-mile Russell Fiord into its namesake 348,701-acre wilderness area to see the 76-mile Hubbard Glacier--North America's largest chunk of tidewater ice--dump countless bergs into Disenchantment Bay. Then bushwhack around the calving mass in the shadow of the huge St. Elias Range, where visitors are few and trails are nonexistent.