Our first real stop was the Lower Geyser Basin. The Lower Geyser Basin encompasses nearly 12 square miles, with a large variety of thermal features, including mud pots, geysers, pools, springs, and fumaroles.

The largest thermal area of the Lower Geyser Basin is the Fountain Group. From the parking area, 0.5 miles of boardwalk trails pass a sizeable assortment of geysers and springs at the edge of quite a large barren region of deposited minerals and very little vegetation. As you walk out along the boardwalk trails, it looks like a giant wasteland with plumes of steam rising everywhere.

The Fountain Paint Pots, temperature 202.8°F is a location where many small vents bubble noisily through thick, clayish mud of varying colors and consistencies. The mud is composed of clay and fine particles of silica broken down by acids and grinding action. The tinting of the mud in colors of pink and gray from iron oxides is derived from the original rock. The bubbling action results in escaping steam and gases - mainly carbon dioxide and hydrogen sulfide. Yes, it definitely smells like rotten eggs.

Just south of here is one of the most colorful pools in this area, the Celestine Pool.

Midway Geyser Basin coming up!