The US Geological Survey has plenty of information about Yellowstone National Park. Some of it’s pretty cool even if you’re not a scientist. For example, there’s a page full of Aerial Photography of the Norris Geyser Basin. They used a radio-controlled camera attached to a helium-filled weather balloon. They were looking at cracks in the earth’s surface around the thermal features at Norris.
Visit the USGS Yellowstone Volcano Observatory for more!