Touring South Yellowstone

On June 20, after our 3-day backpack to Paintbrush Canyon and Leigh Lake, we decided to be tourists for a day in South Yellowstone.  Our destination was West Thumb Geyser Basin and some of the features near Fishing Bridge.

West Thumb Geyser Basin overlooks Yellowstone Lake, which is the largest lake at high elevation in North America.  The Absaroka Mountains can be seen to the east across the lake.  The geyser basin pours an average of 3,100 gallons of hot water into the lake every day, but even with that the lake's average summer temperature is only 47F.  Here is a photo of the lake, looking across the geyser basin:

There are four types of geothermal features in the park:  geysers, which are jets of water coming out of the ground due to pressure of gas (usually carbon dioxide bubbles), or heat, or both; fumaroles, which are vents of steam and other gases; hot springs, which are springs of heated water - often bubbling with carbon dioxide and other gases; and mud pots, which are wet mudholes through which steam and gases escape from underground.  Most of the basins in Yellowstone feature all four types.

Here is a hot spring:

The colored materials in and around a geothermal feature are usually provided by bacteria and other microbes that thrive in hot water.  However, if, as above, the water is clear, the water is so hot that no life can survive in it.  Often such pools are superheated above normal boiling point.  The blue color is due to refraction of sunlight:  the water absorbs all light except the blue you see.

Here is a pool that is super-hot where the water rises into it, but cools at the edges sufficiently to support  life:

Some geysers and other geothermal features exist on the lake bottom.  This is a geyser near the shore of Yellowstone Lake:

Animals are attracted to the warmth of the ground and the warm steam emanating from it - especially in colder months.  This elk cow decided to take a stroll through the basin in midday, seemingly without a care for the humans observing her:

After the West Thumb Geyser Basin, we drove up to Mud Volcano, which has a number of other unusual geothermal features.  On the way, we ran into a "bison jam," which is a traffic jam caused by bison near the road.  Tourists are just about as dumb as the animals, and they will all herd up, blocking the road while they pile out of their cars to photograph the animals.  This fellow didn't seem to care about the hooplah:

Kathy took the bison jam as an opportunity to climb a hill and photograph the herd as it was grazing down near the Yellowstone River:

At Mud Volcano, David inspects the guide to the features while something fumes beyond him:

Here is Mud Volcano itself, temporarily quiescent:

After Mud Volcano, we drove down to Fishing Bridge, which crosses the Yellowstone River below Yellowstone Lake.  Here is a photo looking north up the river from the bridge, toward the lake and the mountains beyond:

Traditionally, visitors were permitted to fish from the bridge, and very frequently, the bridge would be so jammed with fisherpeople, that they would be elbow to elbow, tangling their lines in the water below.  Some decades ago, the park prohibited fishing from the bridge, and it now is simply an attraction for the visitors who drive or walk across it, heading from the center of Yellowstone toward the East Entrance and Cody, Wyoming beyond.

As we headed back to the South Entrance and our campground, we came across another jam - this one an elk jam.  We caught a snapshot of a male elk, all antler proud, with visitors and a ranger milling about in the foreground.  That jam only slowed us down for about 5 minutes.