The Rock Creek CO/sub 2/ project was initiated in 1976 under an ERDA-Pennzoil cost sharing contract. Wells were drilled to develop the 19.65 acre dual 5-spot pilot. Water was injected into the Big Injun formation to pressurize the reservoir and to observe the waterflood response, which was a sharp production kick. Recovery of oil during this time was 11,084 bbl or 564 bbl/acre. CO/sub 2/ injection began in February 1979. By June 1980, 23,842 tons had been injected. A 1.55-acre 4-spot min-pilot was developed, and an additional 12,000 tons of CO/sub 2/ was purchased. To date, an effective CO/sub 2/ volume equivalent to 10% of the total pore volume has been injected into the original pilot injection wells. Currently, 5 wells are on water injection, and the 3 mini-pilot injection wells are injecting CO/sub 2/. These 2 wells will continue CO/sub 2/ injection until an effective volume of CO/sub 2/ equivalent to ca 25% of the total mini-pilot pore volume has been injected. All of the wells then will remain on water injection until the miscible CO/sub 2/ displacement mechanism has been evaluated.