Abstract Oil accumulation on salt domes is either in super-cap sands, cap rock, or lateral sands. West Columbia is an example of a salt-dome oil field which produces only from lateral sands. One 20-acre lease has produced 620,000 barrels an acre in eight years. The Texas Company's Abrams No. 1 was completed on July 20, 1920, and for six weeks flowed at the average rate of 26,500 barrels per day of pipe-line oil.

Abstract The Cut Bank oil and gas field is in Glacier County, Montana, 50 miles east of Glacier National Park, and extends to within 3 miles of the Canadian border. It is 31 miles long and up to 10 miles wide. The field is on the west flank of the Sweetgrass arch. The structure is monoclinal and the regional dip is about 75 feet per mile slightly south of west. The trend of the producing area is parallel with the regional strike. It is still in an active stage of development and as of July 1, 1940, 506 oil wells, 78 gas wells, and 86 dry holes had been drilled, proving 40,000 acres for oil and 55,000 acres for gas production. Average daily oil production was about 11,000 barrels, which also represented the potential for the field, and daily gas withdrawal about 21 million cubic feet. Total oil production to July, 1940, was 18,645,500 barrels and total gas withdrawal 62,890 million cubic feet. Average well depth in the oil area is 2,950 feet. The discovery well, completed in 1926, sought a west extension of the Kevin-Sunburst field when it found a stray sand containing commercial amounts of gas above the objective horizon. Another well found oil lower structurally in the same sandstone in 1929, but active development of the oil field did not take place until 1932. The stray sand was first named the Darling, later renamed the Cut Bank, and is the main reservoir of oil and gas. The Upper Cretaceous Two Medicine, Eagle sandstone, and Colorado shale formations; the Lower Cretaceous Kootenai (lower Blairmore) formation; and the Upper Jurassic Ellis formation are penetrated. The Kootenai lies unconformably on the Ellis. The three producing zones lie in the lower 200 feet (lower third) of the Kootenai and are: the Moulton sand zone at the top, the Sunburst sand zone in the middle, and the Cut Bank sand at the base. The lower Cut Bank or principal producing sand rests unconformably on the Ellis shale. The Kootenai is a continental formation and the source of its sediments and that of the producing sands is believed to have been from the west and northwest from the erosion of a Jurassic landmass occupying the approximate position of the Purcell and Selkirk ranges in southern British Columbia and adjacent parts of Montana and Idaho, 160-300 miles from Cut Bank.