Since completion of the discovery well in March, 1943, 16 producing wells have been drilled in the Steamboat Butte field to the middle of 1947. Oil produced to that time totalled in excess of 4 1/2 million barrels, and the proved reserves of the field rank it among the largest in Wyoming. Oil-producing formations are the Nugget of Jurassic age (oil discovered in March, 1943), and the Tensleep of Pennsylvanian age (oil discovered about a year later). Total ultimate recovery from the Nugget has been estimated as 8 million barrels and from the Tensleep as 50 million barrels.

The structure has an estimated closure of 350-400 feet, and the productive area of the Tensleep is 1,880 acres. The maximum thickness of the oil-saturated section in this formation is 300 feet.

Spotty showings of green oil occur in the Muddy, Dakota, and Lakota sands of Cretaceous age. Considerable gas reserves are present in the Frontier sands of Upper Cretaceous age, from which one gas well is furnishing fuel for lease operations and field development.