Petrified wood is found in many parts of the San Rafael Swell. It often contains uranium, and in the early 1900s-- prospectors talked about "finding a big tree" -- not on top of the ground, but underground. Trees petrified under right conditions turn into a great source of uranium ore, so they would find a small branch of a petrified tree and begin to follow that, hoping to find a large sized trunk. So early prospectors, before Geiger counters, looked for areas that had petrified wood. Another way of finding uranium was to look at the ant hills for yellow rocks. If the yellow rock was there, they knew uranium ore was close by.
