Yellowstone Volcano Observatory
The Yellowstone Volcano Observatory, run by the USGS and University of Utah, is the only observatory tasked with watching a single volcano - the Yellowstone caldera. There is always hydrothermal activity going on in the caldera, which hasn't seen an eruption of new magma in over 3,000 years, so there is a lot of watch on the webcams in the National Park. There are also abundant webicorders and deformation meters - along with temperature gauges in the Norris Geyser Basin - logging every movement of the restless caldera in the middle of North America.
Image: Steamboat Geyser seen in 2000. YVO/USGS
