Travel Reference
In-Depth Information
hours, lasting 9-12 minutes, and reaching heights up to 200 feet. Visible from the road into
the Old Faithful complex if you look back over your shoulder,
Castle Geyser
is thought to
be the park's oldest. It generally erupts every 10-12 hours, reaches 90 feet in height, and
lasts roughly 20 minutes. There is also a 30-40-minute noisy steam phase following the
eruptions.
MM
Firehole River
Since swimming in Yellowstone Lake is not an option unless you are a trained member of
the polar bear club, a dip in the heated (but far from hot!) waters of the Firehole River is one
of the nicest ways to spend an afternoon. The designated and somewhat popular swimming
area is surrounded by high cliffs and some fast-moving rapids both upstream and down-
stream, so the area is not recommended for new or young swimmers. The water temperat-
ure averages 80°F, but this avid swimmer would argue that the temperatures are more likely
in the 70s. Though quite limited, parking is accessible from Firehole Canyon Drive, which
leaves the main road south of Madison Junction, less than 1,000 feet after crossing the river.
There is a toilet available but no lifeguards, so you will be swimming entirely at your own
risk.
Midway and Lower Geyser Basins
Between Old Faithful and Madison Junction, along the pastoral Firehole River, are the Mid-
way and Lower Geyser Basins, technically considered part of the same basin. In 1889, Rud-
yard Kipling dubbed Midway Geyser Basin “hell's half-acre” for its massive hot springs
and geysers. Among the most significant features at Midway is
Grand Prismatic Spring,
a colorful and photogenic spring that was immortalized by painter Thomas Moran on the
Hayden Expedition. It releases some 560 gallons of water into the Firehole River every
minute. At 250 by 380 feet, Grand Prismatic is the third-largest hot spring in the world and
the largest in Yellowstone. Now dormant,
Excelsior Geyser Crater
was once the largest
geyser in the world, soaring up to 300 feet high. Major eruptions in the 1880s led to a
dormancy that lasted more than a century. In 1985, Excelsior erupted continuously for two
days but never topped 80 feet. Today, acting as a spring, it discharges more than 4,000 gal-
lons of heated water every minute.
