Paleontology and geology
Precambrian metamorphic and igneous rocks are exposed in a number of outcrops in the Rocky Mountains, from Yellowstone National Park in the northwestern part of the state to the Medicine Bow Range in southeastern Wyoming. Most of these rocks were formed during several Precambrian mountain-building events. Stromatolites and some possible trace fossils have been found in the southeastern part of the state. These rocks were originally formed from limy sediments deposited on a shallow sea floor.