Yellowstone National Park
From West Thumb, I drove north on Highway 89 to Old
Faithful, the most famous geyser in the world. When I got there, people
were already claiming good seats around the geyser. Though the interval
between eruptions varies each day, the approximate time is 94 minutes.
While waiting for the eruption I took a walk and came across this beautiful
hot spring. Every pool and geyser inside the park has a name, and this
one is aptly named Blue Star.
Relevant links:
http://www.nps.gov/yell/ (The offical national park services site)