Gramp's field, in Archuleta County, Colorado was discovered in 1935, and until 1946 practically no information pertaining to the field had been released for publication. This article sets forth not only details regarding the geology of the field, but also gives data pertaining to operations and production from the drilling of the first well to the close of the operating season in January, 1947. The oil is being produced from the Dakota sandstone (Upper Cretaceous) in which it has accumulated against an east-west fault crossing a north-south anticlinal axis. The average thickness of the producing part of the Dakota sandstone is 152 feet. All the producing wells are at an elevation of more than 8,000 feet and their average depth is 1,250 feet. The producing area of Gramp's ield is 127 acres, and the total production from April, 1937, when installation of storage and pipeline facilities was completed, to January, 1947, has been 2,598,644 barrels. Because of severe winters it is usually necessary to stop field operations from the beginning of January until the middle of April. Gramp's field is unique in that it is privately owned and consequently is free from many State and Federal operating regulations.