Colorado oil production typically accounts for about one percent of the annual U.S. total; most of this production occurs in the Denver and Piceance basins. As of the end of 2009, Colorado was 10th in the nation for both liquid petroleum reserves and production. Two of the nation's 100 largest oil fields by proved reserves are found in Colorado: Wattenberg (13th) and Rangely (74th). Colorado has two oil refineries in Commerce City north of Denver. 

OIL SHALE
Colorado also has the world's largest resources of oil shale which is neither oil, nor shale.

NIOBRARA SHALE OIL
To learn about Colorado's new Niobrara oil boom, click here.

To learn about hydraulic fracturing in the Niobrara and its relation to fresh water aquifers, click here.