There are presently over 200 wells in Montana and North Dakota that produce from, or have indicated pay, behind pipe in the Duperow Formation. Production is primarily confined to the basin center, decreasing greatly as the shallower rim of the basin is approached. There is no production from the Duperow Formation in the Canadian portion of the Williston basin.

Production in the Duperow Formation is primarily from dolomitized stromatoporoid-assemblage patch reefs that occur in the lower unit of the formation. Published work by others concisely defines the stratigraphy, paleontology, and facies subdivisions within the Duperow Formation. The formation consists of series of distinctive shoaling-upward carbonate sequences, and contains cyclic or repetitious bedding characteristic of the formation.

There appear to be three types of traps in the Duperow Formation reservoirs in the Williston basin. The structural type is most common on the Nesson anticline. The structural-stratigraphic type is the most common trap found in the Billings nose area. The unconformity-stratigraphic type is uncommon and found only at Seven Mile and Ollie fields in Montana.

The growth of stromatoporoid bioherms appears to have been influenced by tectonic activity. Many structurally positive areas, such as the Billings nose and the Nesson anticline in North Dakota and the Poplar dome and Sweetgrass arch in Montana, have stromatoporoid biohermal accumulations. These areas, probably slight topographic expressions during Duperow deposition, apparently offered optimum growth position for framework builders.

A stromatoporoid bioherm is interpreted to be the reservoir at Ridgelawn field, Montana. Eight wells appear to be capable of production from the basal portion of cycle 3. The wells appear to define a patch reef that is oriented northwest-southeast and is perhaps 1-1.5 mi (1.6-2.4 km) in its longest dimension.

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