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This trail leads to unusual geyserite forms named Thermos Bottle Geyser, Sunning Seal, & Dog's Head.

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7,987' 2,434 m


7,346' 2,239 m


676' 206 m


677' 206 m



Avg Grade (5°)


Max Grade (21°)

Dogs No Dogs

Features Geological Significance · Hot Spring · River/Creek · Views

Backcountry hydrothermal areas are not equipped with boardwalks. Scalding-hot water or steam can lie beneath a thin crust. Use extreme caution when entering Monument Geyser Basin. Stay on well-worn paths and away from areas devoid of vegetation. Remember, careless activity in backcountry thermal areas is not only dangerous, but destructive to these rare and fragile features.


Monument Geyser Basin was discovered in 1878 and quickly became a favorite tourist attraction. Visitors marveled at its unusual geyserite formations which later received fanciful names like Sunning Seal, Dog's Head and Sperm Whale. Now you can rediscover this unique area and find these remarkable features.


The trail leaves the parking area and travels 0.4 miles north along the Gibbon River as it babbles its way into Gibbon Canyon. The stream was named for General John Gibbon, a veteran of the Civil War and later Indian wars, who was one of the first to explore this river in 1872. Soon the trail reaches the edge of Gibbon Meadows, where elk are commonly seen grazing.

The trail turns sharply to the left and begins a 0.7-mile steep climb up more than 600 feet through a lodgepole forest thoroughly burned in 1988 by the North Fork Fire. At the 1.1-mile mark, you reach the top and get an impressive view down Gibbon Canyon. The trail then swings right and skirts the edge of Monument Geyser Basin, an oblong collection of acid mud pots, sulfurous pools, steam vents, and inactive geysers. The ground here is very unstable. Do not cross the basin. Instead do your exploring from the outer edge of the basin near the trees or other vegetation.

Park Superintendent P.W. Norris discovered this basin in 1878. He named it for the gravestone-like sinter cones it contains, commenting there were deposits "strongly suggesting the work of human hands; some ancient memorial to the dead."

The most impressive feature in the basin is eight-foot Monument Geyser (also known as Thermos Bottle Geyser), which lies elevated on the basin's western side. Until the 1930s, it commonly erupted to a height of 15 feet. It remains active, but now merely hisses, sputters and steams. As its sinter cone grows taller, Monument Geyser is apparently slowly sealing itself off at the top.

Most of the other interesting features in the basin have already sealed themselves and become dormant. Their unusual shapes, however, make them the stars of this run. You'll find these extraordinary features to the right of Monument Geyser. Use your imagination to see how many of the following well-named features you can recognize: Sperm Whale, Sunning Seal, Jumping Seal, Dog's Head, and Dog's Tail. When you have finished your exploring, retrace your steps to the trailhead.

Thanks to guidebook author, Tom Carter, for sharing this trail description. To learn more about visiting Yellowstone, check out his book, Day Hiking Yellowstone.

Flora & Fauna

The trail skirts the edge of Gibbon Meadows, where elk are commonly seen grazing. Elk, or "wapiti" as Native Americans called them, are the most numerous of Yellowstone's large animals. Mature males stand five feet high and weigh 750 pounds or more. Like all members of the deer family, the bulls grow a new set of antlers each year. In the summer the antlers are covered with blood vessels (called "velvet") that carry nourishment to the rapidly growing bone. In the fall they scrape their antlers against trees and other objects to remove the velvet and prepare for rutting season.

History & Background

Park Superintendent P.W. Norris discovered Monument Geyser Basin in 1878. The following year Norris constructed a trail for tourists to visit the park's newest attraction. Because the trail was considered too steep for horses, visitors had to dismount and walk up. As a result, this trail and the Seven Mile Hole Trail are the first hiking trails in Yellowstone.


Shared By:

Tom Carter

Trail Ratings

  4.2 from 11 votes


in Norris


  4.2 from 11 votes
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Monument Geyser Basin
Mar 13, 2019 near Norris…, WY
Beginning of trail
Mar 13, 2019 near Norris…, WY



Current Trail Conditions

Minor Issues 52 days ago
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