West Thumb Geyser Basin, Yellowstone National Park, WY

West Thumb Geyser Basin is one of the numerous stops within Yellowstone National Park, Wyoming visitors might wish to see. The park is spread over several hundreds of acres, and could literally take weeks to explore. West Thumb Geyser Basin is one of the highlighted areas for visitors coming in the south entrance. West Thumb is at the junction where the loop to the east and west entrances converge. It is before Old Faithful when coming from the south.

Yellowstone National Park is broken into two types of hydrothermal features: geysers and hot springs. West Thumb is a geyser which means water will rise from underground as it is heated and pressure builds. The water will then shoot from a cone structure, often made of limestone. There are also some mudpots and fumaroles along the way in the park.

West Thumb Geyser Basin's walking tour will explain the various Yellowstone features and what makes them distinctive for visitors on the trail. During a walk along the West Thumb Geyser trail visitors will be brought to an overlook of Yellowstone Lake. The lake is the largest one at such elevations in North America. In winter the lake's surface will freeze, so that it appears as a white sheet for miles. In summer the lake can be calm, a little choppy, and very interesting depending on the weather around it.

Also on this walking tour is Abyss Pool. The Abyss Pool is 53 feet at its deepest point. It is also a hot spring. The pool can vary from turquoise blue to emerald green based on the depth of the water. The spring was first noted in 1883. Another pool or hot springs can be found on the tour. This one is called Black Pool, named because the pool was actually black in color. The water temperatures were lower than other hot springs allowing the microorganisms growing in the water to turn a very dark green, looking almost black. The temperature of the water rose in 1991, killing the microorganisms.

An amazing point along West Thumb Geyser Basin is the Big Cone. The Big Cone is the largest sinter cone, which is also in Yellowstone Lake. Big Cone can be submerged in the lake depending on the water flow of the mountains. Fishing Cone is next on the tour. It is on the shore of the alpine lake. In the past mountain men used the lake to fish, which is why it was named Fishing Cone. This naming occurred in 1870 by the Washburn Expedition. Fishing is sadly no longer possible.

In the 1920's and 1930's Lakeshore Geyser would erupt 50 feet in the air. There were also two geyser vents. The smaller geyser vent is typically closed until August each year.

West Thumb Geyser Basin has numerous stops for visitors to spend a little time. Other stops along the trail include Seismograph and Bluebell Pools, Thumb Paint Pots, Surging Spring, Ledge Spring, Collapsing Pool, Thumb Geyser, and many others.