This diagram shows the features within the Midway Geyser Basin, the largest of which is the colorful Grand Prismatic Spring.
The water from the springs and pools in the area eventually makes its way to the Firehole River flowing below. Even here you could feel the heat from the water as it passed by. The sulfur smell was quite strong also.
A boardwalk trail meanders through the area giving you an “up close” look at the pools and springs. This is at the lower edge of Excelsior Geyser, which is currently dormant.
A panoramic view of Excelsior Geyser from its northern side (as with all photos, double-click on the image to view a larger version). Water flows from the geyser pool, down the hill, and into the Firehole River.
Water from the Grand Prismatic Spring flows into the Excelsior Geyser.
A view of Excelsior Geyser from its southwestern side.
Looking to the west toward the boardwalk around Grand Prismatic Spring from the boardwalk on the west side of Excelsior Geyser. The water is only a few inches deep between the two features.
The Grand Prismatic Spring. Colorful tendrils are formed by the heat-loving microorganisms where the water flows over the edge of the spring.
Looking back toward Excelsior Geyser.
The Opal Pool. You can just barely see Firehole River in the upper center of the photograph and the mountains way off in the far distance.
It was late in the evening when I headed back to the campground. This photo was taken along the western side of the southern loop in part of the Hayden Valley – that's the Yellowstone River flowing through the valley.
It had been a great day despite a few quick moving rain showers. The temperature was in the upper 60s and lower 70s all afternoon – great weather for sightseeing and playing the tourist!