To reach the site, from the U.S. Hwys. 191/89 intersection near West Yellowstone, take the Grand Loop Road/U.S. Hwy. 89 east and north about 30 miles toward the Montana border. A couple of parking areas can be found off the highway's left/west side with walking paths leading from them into the hot springs area.
Sunrise over the hot springs (photo courtesy of Yellowstone NPS); a series of connected trails cut through the heart of the geological feature:
Overview map of Mammoth Hot Springs with key geological features (illustration courtesy of Wikipedia):
Among the best lots the park is the one immediately north of the road that turns off the highway to the horse corral. A 0.8-mile hike (outlined in yellow) then can be followed through the hot springs:
The white terraces are created by dissolved limestone that crystalizes as the hot spring brings it to the surface:
Sunlight low on the horizon casts a warm glow across the terraces:
Some of the terraces can grow quite tall. They are several thousand years in the making:
Steam from the hot springs roils off the terraces:
Looks like a scene out of winter, but this photo was taken in summer:
Brown algae that thrives in hot environments grows on some of the terraces; other algae colors found at the hot springs are red, orange and green:
Learn about other great national park day hiking trails in my Best Sights to See at America’s National Parks guidebook.
