UPPER GEYSER BASIN

Upper Geyser Basin covers a surface of about 10 km ², over 180 of the 200 (250) geysers of the park, including the largest and most impressive of the park, and many hot springs. A circuit, the Geyser Hill Nature Trail (starting at the Old Faithfull Full Geyser, approx. 2.5 km), allows you to admire the main geysers and other attractions. The five largest geysers are regularly submitted by the staff: Castle, Grand, Daisy, Riverside, Old Poli.

North-west of the Old Faithhole River, on the other side of the Firehole River, the Giantess Geyser, which runs irregularly up to 60 meters high for periods up to 36 hours, is reached. Nearby you can see the Boakettle boil water (kettle) and Geyser Sponge (sponge), which owes its name to the shape of its crater. Isolated, isolated, Solitary Geyser. Beyond the Desert Sponge, northwestern, Geysers Lion Group, Lioness, Big Club and Little Club.

The main road leads to Liberty Pool, Sawmill Geyser and Spasmodic Geyser. A path crossing the Firehole River allows you to go to Crested Pool and Castle Geyser, probably the oldest active source of the park.

The main trail then obtains to the Grand Geyser (jet of 60 meters high), which communicates with the close Turban Geyser. Later, Beauty Pool and Chromatic Pool are in turn. Then we cross the Firehole River again to reach Inkwell Springs near Giant Geyser, broken crater. Farther away, the Grotto Geyser, whose dome has several niches almost to man's height, leads to water jets.

Next, the trail runs along the bank of the Firehole River and leads to Riverside Geyser (on the other shore) that spreads its jet into the stream and then beyond another bridge to the Fan and Mortar Geysers, connected by underground; Later, the Morning Glory Pool is a tinted basin of the most tender colors, named because of its resemblance to the ipomée (morning glory) flower.