Elevation: 7,800 ft.
The thermal features at West Thumb are not only found on the lake shore, but extend under the surface of the lake as well. Several underwater hydrothermal features were discovered in the early 1990s and can be seen as slick spots or slight bulges in the summer.
During the winter, the underwater thermal features are visible as melt holes in the icy surface of the lake. The surrounding ice can reach three feet (one meter) in thickness.
Early visitors would arrive at West Thumb via stagecoach from the Old Faithful area. They had a choice of continuing on the stagecoach or boarding the steamship Zillah to continue the journey by water to Lake Hotel. The boat dock was located near the south end of the geyser basin near Lakeside Spring.