Polymer-gel treatments in injection wells were evaluated for improving sweep efficiency in the D Sandstone reservoir at the Sooner Unit, Weld County, Colorado. Polymer treatments of injection wells at the Sooner Unit were expected to improve ultimate recovery by 1.0 percent of original-oil-in-place or 70,000 bbl of oil. The Sooner D Sand Unit was a demonstration project under the U. S. Department of Energy Class I Oil Program (DE-FC22-93BC 14954) from which extensive reservoir data and characterization were obtained. Thus, successful application of polymer-gel treatments at the Sooner Unit would be a good case-history example for other operators of waterfloods in Cretaceous sandstone reservoirs in the Denver Basin.