The Bonanza pool, a Tensleep sand discovery of late 1950, is located on the east flank of the Big Horn basin northeast of Worland, Wyoming. The discovery well, drilled by the Bonanza Oil Company, attracted considerable attention due to the high gravity of the oil at relative shallow depth and to the thick pay section. As of December 5, 1951, the pool had twenty flowing wells, which have defined an area of approximately 595 productive acres. Productive closure is 210 feet.

The structure is a northwest-southeast-trending asymmetric fold with a steep mountainward flank. The fact that little to no surface closure is present in Upper Cretaceous shales accounts for the late testing of this long long-known surface structure. The Tensleep sand is found at depths of approximately 2,700 feet. The sand has a gross thickness of 230 feet.

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