Thursday started out as a visit to West Thumb Geyser Basin. Yellowstone Lake is the largest lake in YNP, and the largest body of freshwater in the US above 7000 ft. The lake is shaped roughly like a hand, and West Thumb is, well, the thumb.
It’s also a very active thermal feature in YNP, with all of the usual hot springs, geysers, steam pots, mud pots, etc etc etc, and the basin is right up along the shore of the lake.
Just as we finished walking the basin and were about to leave, a large visitor walked out of the forest.
Heading down the road from West Thumb, we stopped again at the Old Faithful area to finish what we started on Sunday. A couple miles of trail and boardwalk brought us past a bunch of active geysers, and to the most beautiful spring so far, Morning Glory Pool.
Susanne stopped off and made a new friend. The ravens in YNP are huge and have the funniest voices. Kind of a croaking noise, totally unlike any bird I know.
A quick hustle back to the visitor center and we caught another of the movies about the park, explaining some of the science behind all the hot spots. Normally, molten material is in the earth’s mantle, at 1800 miles below the surface. About 640,000 years ago, Yellowstone was a supervolcano over 50 miles wide, exploding and spewing lava across the land, but today the molten rock hovers just underground at only about 4 miles deep. Surface water percolates downward, gets flash boiled to steam, and then pushes its way back up. The constant up and down, water to steam and back, makes YNP what it is. Someday, the magma will win and Yellowstone will again blow its top. Imagine a 50 miles wide volcano in the central US. That’ll put a damper on Wyoming’s tourist industry.
Mike and Susy's Spirit of Discovery 
Leave a comment