Within a mere two square miles of the desert outside the Salton Sea there are enough gryphons, gas vents, salses, and mudpots to delight any geological oddity enthusiast.
At the Davis-Schrimpf Seep Field, geothermal mudpots announce themselves by belching gray bubbles from short sludge volcanoes. The bubbling seep fields are caused by the buildup of carbon dioxide beneath the surface of the earth, which pushes to the surface through the water table and sediment. As such, these aren't true volcanoes. They aren't boiling hot, merely warm. They can be quite stinky though, and gas bursts can range from a quiet "blurp" to a noisy eruption.
The salt content of Davis-Schrimpf Seep Field mud is so high that when it dries on the ground it forms a white crystalline top layer. When visitors walk across its surface it crunches like hard snow.