Abstract The Wilson Creek field is situated in mountainous terrain of Rio Blanco County, Colo. It was discovered in early 1938 and produces from both the Morrison and Sundance sands of Jurassic age. The underlying Sundance reservoir is fully developed with 18 wells; no dry holes have been drilled. The overlying Morrison reservoir of greater areal extent is almost completely developed with 21 producing wells and three dry holes around the periphery of the field; in addition, all or most of the 18 inside Sundance wells will eventually serve to exploit the central portion of the Morrison reservoir. The Morrison reservoir was moderately undersaturated with an initial average pressure of 2,180 psig and a bubble point pressure of about 1,100 psig; a partial water drive is in effect. A top structure gas injection program was started early in the life of the pool, resulting in a dampened pressure decline rate and increased oil recovery. The Sundance reservoir is greatly undersaturated and exhibits a prolific water drive. Individual well fluid capacities are generally high and edgewater-type encroachment is evident throughout all producing levels. A down-flank gas injection project has recently been instigated. The field is completely electrified and power is generated in a field plant. The operators own and maintain an 18-mile pipeline through which over 7,000 BOPD may be shipped by gravity flow. Major operational problems are related to extended winter periods of extreme cold and deep snow, rough terrain, paraffin accumulations, water disposal, and high water:oil and gas:oil ratio control. Introduction The Wilson Creek field is located on the northern edge of Rio Blanco County, Colo., about 25 miles southwest of Craig, the only railhead in the area, and 10 miles north of Meeker. For geographical orientation see Fig. 1. The local terrain is mountainous, being in the more rugged portion of the regional Danforth Hills anticlinical trend. It is readily accessible year-around via well-maintained county roads connecting the local federal and state highway system.