Compared to Upper and Lower Geyser Basins, Midway Geyser Basin is quite small. But it has two very large and notable tenants: Grand Prismatic Spring and Excelsior Geyser. Parking was once again a problem, but we eventually found a spot.
In the late 1800s, back when it was erupting regularly, Excelsior Geyser was the largest geyser in the world. (Steamboat Geyser in the Norris Geyser Basin is the current champion.) It sometimes reached 300 feet high, and, since it is a fountain geyser, almost as wide. Then, after decades of violent eruptions, it abruptly stopped in 1890. The theory is that its own ferocious eruptions somehow damaged the underground plumbing. It has only erupted a few times since (1878, 1901, and 1985). Today it is classified as a mere "hot spring". But it still pumps 4,000 gallons of near-boiling water into the Firehole River every minute. That's enough to fill nine Olympic-size swimming pools per day.
It's a shame they don't have an elevated boardwalk so you can get the full perspective of Grand Prismatic Spring. The pool is 370 feet in diameter (a larger surface than Lambeau Field, including the sidelines and end zones.) It's the largest hot spring in the park. But the appeal isn't just its size. It's its color. While difficult to appreciate from a ground-level photo like this, the aerial view is absolutely spectacular. The outer ring is a fiery orange, and it radiates out in a sunburst pattern. The next ring is a brilliant yellow, followed by a narrow band of neon green. But the center...ah, the center. It takes your breath away. It's the deepest, most intense cobalt blue you've ever seen.
In the late 1800s, back when it was erupting regularly, Excelsior Geyser was the largest geyser in the world. (Steamboat Geyser in the Norris Geyser Basin is the current champion.) It sometimes reached 300 feet high, and, since it is a fountain geyser, almost as wide. Then, after decades of violent eruptions, it abruptly stopped in 1890. The theory is that its own ferocious eruptions somehow damaged the underground plumbing. It has only erupted a few times since (1878, 1901, and 1985). Today it is classified as a mere "hot spring". But it still pumps 4,000 gallons of near-boiling water into the Firehole River every minute. That's enough to fill nine Olympic-size swimming pools per day.
It's a shame they don't have an elevated boardwalk so you can get the full perspective of Grand Prismatic Spring. The pool is 370 feet in diameter (a larger surface than Lambeau Field, including the sidelines and end zones.) It's the largest hot spring in the park. But the appeal isn't just its size. It's its color. While difficult to appreciate from a ground-level photo like this, the aerial view is absolutely spectacular. The outer ring is a fiery orange, and it radiates out in a sunburst pattern. The next ring is a brilliant yellow, followed by a narrow band of neon green. But the center...ah, the center. It takes your breath away. It's the deepest, most intense cobalt blue you've ever seen.
