In this way you will avoid the steep stairs to the top of the Main terrace. On the Upper Terrace Drive be sure to stop at the Main Terrace Overlook and take the trail on the far right to Canary Spring. For the past few years, Canary Spring has been truly spectacular. The temperatures here are lower than at the geyser basins. In most cases, what looks like boiling is actually just the evolution of gasses, especially carbon dioxide.
Midway is home to two of the largest thermal features in Yellowstone.
The various colors of the cyano-bacteria around the pool are quite pretty. Excelsior Geyser was the largest geyser in the world in the 1880s. Now it is just a very large crater that emits a copious amount of water. After nearly 100 years of inactivity, it had some minor eruptions in 1984. West Thumb is a small collection of geysers and hot springs located on the shore of Lake Yellowstone.