Grand Prismatic Spring and Excelsior Geyser Crater
Excelsior Geyser Crater is about 100 yards north of Grand Prismatic Spring. These two features are the main attractions in Midway Geyser Basin. Excelsior last erupted in the 1880s, throwing water perhaps as high as 300 feet and discharging enough water to raise the level of the nearby Firehole River by up to a foot. This geyser when active, was the largest ever recorded in Yellowstone. Excelsior Geyser Crater is still producing an impressive amount of hot water, about 3000 gallons a minute.