Lamar Valley, WY 7 miles (Easy)
For concentration and variety of big-ticket wildlife, Yellowstone National Park’s Lamar Valley beats all other spots in the Lower 48: Bears (grizzly and black), wolves, elk, and bison all roam the grasslands surrounding the Lamar River. For the best viewing, follow the well-maintained Lamar River Trail 3.5 miles south from the trailhead (then turn back).
Season Year-round for wolves and bison, spring for bears, winter for elk
Swiftcurrent Pass, MT 15 miles (Difficult)
This one-way route in Glacier National Park–which traces the Continental Divide and then a glacial stream–should be on every hiker’s life-list. It crosses fields of glacier lilies (grizzlies love the bulbs) and steep terrain favored by bighorn sheep and mountain goats (left). From Logan Pass trailhead, take the Highline Trail and connect to Swiftcurrent Pass, then descend through Many Glacier Valley, past turquoise icemelt pools.
Castle Peak, ID 12 miles (Difficult) Fair trade: The rock is notoriously loose on the way up, but the view is famously jaw-dropping on top. To reach this peak in the White Cloud range, follow the Washington Creek and Chamberlain Creek Trails for five miles, reaching the Chamberlain Lakes at 9,200 feet. Then scramble (carefully!) up talus for 2,615 vertical feet to the summit, where you’ll overlook 25 lakes and the genuinely sawlike Serrate Ridge. Pack trekking poles for the descent via the same route.
Info (208) 774-3000