Castle Geyser has the largest cone and may be the oldest of all geysers in the basin. Its eruption pattern has changed considerably throughout its recorded history. Castle is currently erupting about every 10 – 12 hours. A water eruption frequently reaches 90 feet (27m) and lasts about 20 minutes. The water phase is followed by a noisy steam phase lasting 30 – 40 minutes.
I was startled when I came upon this. I don’t research places much before I go. I like to be surprised. We approached Castle Geyser from the other side, coming uphill. The geyser was above us. The steaming white cone is so weird. I felt like I was on another planet.
Yellowstone makes you realize what the Earth is like another planet, if you look beneath the surface! As a park ranger once said, “Yellowstone is a window into the Earth.”