Old Faithful Inn

Built in 1897, this is the oldest structure in the Old Faithful area still in use. The "knotty pine" porch is a popular resting place for visitors, providing a great view of Geyser Hill. (The oldest building at Old Faithful was built as a photo studio in 1897 for F. Jay Haynes. It used to be 700 ft southwest of Beehive Geyser and about 350 ft northwest of the front of the Old Faithful Inn, but it now stands near the intersection of the Grand Loop Road and the fire lane, near the crosswalk.).

Yellowstone, as a whole, possesses close to sixty percent of the world's geysers, and the Upper Geyser Basin is home to the largest numbers of this fragile feature found in the park, including the iconic "Old Faithful" geyser. Old Faithful, the world's most famous geyser, has large eruptions occurring an average of about once every eighty minutes, although the timing between each eruption varies by as much as an hour and has been increasing over the years. Rangers are able to predict the geyser's eruptions to within about ten minutes, provided the duration of the previous eruption is known. In addition to Old Faithful, this basin contains an additional 150 geysers within a one square mile (0.25 mi2) area; of this remarkable number, the eruptions of Castle, Grand, Daisy, Riverside, and Old Faithful are predicted regularly by the naturalist staff. In addition to geysers the area is home to numerous hot springs. Boardwalks allow access to the most interesting areas. Do not leave the trails; the surface here is thin and unstable and has a real chance of depositing you in a boiling pool of water if you walk where you're not supposed to.

This is the most easily reached waterfall in the district. A marked pullout just south of Old Faithful and a short walk from the car offers the visitor easy access to view this 125 ft cascade.

This backcountry geyser basin is easily reached by a 5 mi round-trip hike that follows an old, now-closed road from the trail-head south of Old Faithful. Lone Star Geyser erupts about every three hours. There is a logbook, in a cache near the geyser, for observations of geyser times and types of eruptions. Bicycles can make it most of the way to Lone Star.

This geyser basin is on a hill overlooking the Firehole River. Smaller in size than the other geyser basins in the area, the runoff from its thermal features flows into the river, leaving steaming, colorful trails in its wake. In particular, Excelsior Geyser reveals a gaping crater 200 x with a constant discharge of more than 4000 gal of water per minute into the Firehole River; this geyser once erupted so violently that it may in fact have blown itself up, and no eruptions have since occurred. Also in this surprising basin is Yellowstone's largest hot spring, the beautifully-colored Grand Prismatic Spring. This feature is 370 ft in diameter and is 160 ft deep. The Fairy Falls trailhead provides access to an observation platform on the hill behind the spring that lets you get an elevated view of the entire basin.

This lake is on the Continental Divide at Craig Pass in 1891. Isa Lake is noteworthy as probably the only lake on earth that drains naturally to two oceans backwards, the east side draining to the Pacific and the west side to the Atlantic.