Mud pots are hot springs of boiling mud . Bubbles rise through the viscous liquid, then pop, leaving rings on the surface. Algae or particular minerals may tint the mud various colors, as in the Fountain Paint Pots of the Lower Geyser Basin. Springs and geysers in Norris Basin are hotter than any others in the park. This suggests that magma is nearest to the surface in that area.
Visitors can follow paths around many of the geysers and hot springs.
Here a steaming hot spring lies in front of an erupting geyser. This large hot spring is located at the West Thumb of Yellowstone Lake. In places, it is possible to peer through clear water into the depths of a hot spring . When the water reaches the surface and cools, a dense form of limestone called travertine precipitates in multi-level terraces . Algae growing in the hot water stripes the travertine in orange, brown and yellow.