Near the Salton Sea shore, at the corner of Davis and Schrimpf Roads, you can find Mud "Volcanos". There you can see some cones built up out of viscous mud that bubbles up through central vents. This area is near a formerly commercial carbon dioxide gas field. Pressurized carbon dioxide gas is probably the driving mechanism for the bubbling mud. The age of these particular mudpots is not known but survey reports in the late 1800's and early 1900's reported mudpots and steam vents in the area.
On Hot Mineral Spa Road, just off Highway 111, you will find the Wister Mudpots. The fluid level in these mudpots varies throughout the year. Notice that several mudpots located next to each other have different fluid levels and notice the different colors in the mud. The temperature of the fluid is slightly higher than the ambient air temperature which indicates an anomalous heat source.