Excelsior Geyser Crater is located in Midway Geyser Basin. In the 1880s Excelsior erupted in bursts 50 to 300 feet high. The thermal violence formed the jagged crater and apparently ruptured the underground system, causing eruptions to cease after 1890. On September 14, 1985 Excelsior roared back to life with 47 hours of major eruptions. It is impossible to predict when this dormant but powerful geyser’s next eruption will occur.