Travel Reference
In-Depth Information
Upper Geyser Basin
Upper Geyser Basin stretches in a right triangle from Old Faithful Geyser north and west,
mostly along the Firehole River. The hot springs and geysers draw upon the local groundwater
for their source of water but also upon deep underground reservoirs. This hydrothermal area
contains more than 20 percent of all the geysers in the world, as well as thousands of non-
erupting hot springs. T. Scott Bryan, in his book,
The Geysers of Yellowstone,
writes: “To prop-
erly experience the Upper Geyser Basin, one should spend at least two or three days to wait
for the large and famous geysers to erupt, as well as to enjoy the smaller features. There are
minor details to be observed in the basin, too—the colors, wildflowers, forest life, thermophil-
ic communities, and so on—many of which are found nowhere else in the world. To spend
less time is to cheat oneself.”
What exactly is a geyser?
A geyser is a hot spring that throws forth jets of water and steam intermittently. As you
wander through the area, try to guess which seemingly placid hot pools or deep holes may
be active geysers, even if they don't erupt while you're watching. Here are some telltale
signs of active geysers:
• A deep or wide white crater that does not look cracked and dry
• Areas downhill from the crater that are devoid of life due to hot water
• Puddles of water around a crater when it hasn't been raining
• Dead but standing trees nearby, indicating a relatively new geyser
• Concentric rims or formations of the pale brittle rock called geyserite
The Old Faithful interchange bypasses most of the thermal features. Before it was built,
the Grand Loop Road ran past many of them, including Morning Glory Pool and Grotto and
Castle Geysers. The only current access to these fascinating but sensitive features is by foot or
bicycle. Many bicyclists here are members of the Geyser Observation and Study Association
(see
page 361
).
Vandalism to the geysers and pools has decreased noticeably since the rerouting of traffic,
but the road relocation has made it difficult for older or disabled visitors or for those with very
