Mud Volcano Area in Yellowstone National Park, a UNESCO World Heritage site, is full of gray colored springs and mudpots. Hydrogen sulphide is responsible for the terrible rotten egg smell that is common in the area. Unfortunately, the trail up into the hills was closed during my visit. I was only able to see a few features of this unique area.
Dragon’s Mouth Spring
The first feature I visited was Dragon’s Mouth Spring. In 1912, it was named by a visitor who believed the water surging out of the cave looked like the lashing of a dragon’s tongue. Until 1994, it had a beautiful green color and would forcefully splash water all the way up to the boardwalk.
Next was Mud Volcano. In 1870, this geyser would shake the ground with force and spew mud up into the trees. Only two years later, it became the bubbling pool of muddy water it is today.
Mud Caldron is further down the boardwalk. It looks like a large pool of muddy water. The hill next to it is Cooking Hillside. Before 1978, the hill was covered with a dense forest. After a series of earthquakes, the ground temperature rose to almost 200°F, “cooking” the trees and leaving the hill bare.
Finally, the path up the hill can give you a nice look at Mud Geyser. In the late 19th century, Mud Geyser would erupt every few hours, shooting mud up to 50 feet into the air. It was dormant by 1927.
When the rest of the trail isn’t closed, it leads to a few more muddy springs, fumaroles, and mudpots. Up Grand Loop Road across the street is Sulphur Caldron, which is also worth stopping at.