The Midway Geyser Basin is one of the major features enroute to Old Faithful and can be reached from the parking area by walking across the bridge spanning the Firehole River.
This geyser basin, though small in size compared to its companions along the Firehole River, holds large wonders for the visitor. Excelsior Geyser reveals a gaping crater 200 x 300 feet with a constant discharge of more than 4,000 gallons of water per minute into the Firehole River. Excelsior Geyser erupted on September 14, 1985 to the height of 55 feet and lasted 46 hours. The last known eruption occurred in 1888. Also in this surprising basin is Yellowstone's largest hot springs, Grand Prismatic Spring. This feature is 370 feet in diameter and more than 121 feet in depth.