Nearby, poke your head into the Mammoth Hot Springs Hotel (+1 307 344 7901) lobby, built in the ’30s, then head for Mammoth Hot Springs proper—the creamy brow of steaming rock beyond the buildings. Upper Terrace Drive curves among the large travertine terraces and mounds and passes dead limber pines more than 500 years old. For a close-up look at active springs trickling over stair-stepping terraces, follow the nature trail through the Main Terrace area, where hot water deposits some of the two tons of travertine accumulated here daily.Double back to the hotel and turn right on the Tower-Roosevelt road, part of the Grand Loop Road. Soon you’ll come to Undine Falls, a lovely twin falls that drops 60 feet [18.3 meters], then 50 feet [15.2 meters] through a narrow gorge.
Even if you’re not caught in an endless column of RVs, get off the main drag and follow Blacktail Plateau Drive through rolling sagebrush hills and evergreen forests—good country for spotting pronghorn, elk, and deer. Shortly after rejoining the main road, take the right-hand turnoff for Petrified Tree, one of many redwoods in the region buried alive by volcanic ash 50 million years ago and turned to stone.
Rustic Roosevelt Lodge (+1 307 344 7311) was built in 1920 and named for Teddy Roosevelt, who camped near here during his 1903 junket to dedicate his namesake entrance arch. Near the ranger station, have a look at the Tower Soldier Station, one of three such Army outposts that survive. On the way to Canyon Village, stop to stretch your legs at Tower Fall, where a short trail leads to an overlook above a 132-foot [40.2-kilometer] cascade spilling from a cluster of coarse volcanic towers.
Beyond the falls, the road climbs above a broad valley drained by Antelope Creek—prime grizzly habitat and one of the best roadside locations in the park to spot the gre at bears. After scoping the valley for grizzlies, drive to the Mount Washburn parking area and consider a walk to the top of this extinct volcano. The moderate 3-mile [4.8-kilometer] hike leads through spectacular subalpine meadows where bighorn sheep often munch on wildflowers. It ends at a fire lookout with a 50- to 100-mile [80.5- to 160.9-kilometer] panoramic view.
As the road continues its climb toward Dunraven Pass, it’s hard to miss the effects of the great Wolf Lake Fire that burned through here in 1988. Many of the large mammals that died during that amazing season were killed among the cliffs of this rugged area, trapped by the swift fires.
A few miles beyond the pass, stop at the Washburn Hot Springs Overlook for a view of the Grand Canyon of the Yellowstone—a ragged trench cut through the forests of central Yellowstone. Here, too, you get a feel for the immense size of the Yellowstone Caldera, which stretches south 35 miles [56.3 kilometers] from the slopes of Mount Washburn to the Red Mountains.