North Dakota is a great location for fossil hunting. Enthusiasts come from all over to participate in public digs. North Dakota is rich in prehistoric discoveries due to its geography. Most of its surface is made of sedimentary rock that has not been touched by glaciers, creating ideal conditions for finding fossils. While most of the discoveries are by people looking for them, every once in a while someone stumbles across an ancient sample by accident. This is what happened at an oil drilling site in 2005, reported on this date in 2007.