The discovery in 1950 of this 75-million bbl complex of oil pools was based largely on the belief that a large stratigraphic "Dakota" oil pool would be found updip from a well in which permeable oil-saturated "Dakota" sandstone was found to be water-bearing. The oil show in the well, which was on the east flank of the Big Muddy anticline, was 1,903 ft (580 m) structurally lower than the lowest oil-productive "Dakota" on the crest of the anticline, where this unit had been productive since 1922.

A 12,500-acre lease block was assembled updip from the inferred oil-water contact and downdip from an inferred permeability barrier along the east flank of the Big Muddy anticline. The discovery well tested oil in an upper Muddy sandstone and was deepened to the "Dakota," in which it was completed as an oil producer.

The "Dakota" all reservoir is a complex of interlocking sandstone bodies deposited in a shallow sea. Although "Dakota" oil reserves basically are trapped updip by a permeability barrier, a spectacular tilt of 750 ft (230 m) in the oil-water contact along the south side of the pool argues, in part, for a dynamic balance between water flow and the oil accumulation.

The lower Muddy pool occurs in point-bar sandstones from a filled stream channel which meandered across a well-defined meander belt. Only two positions of the stream channel are evident; therefore, the meander belt is only partially filled.

The third set of stratigraphic oil pools within the South Glenrock oil field is found in four marine bar sandstones which were deposited after marine burial of the earlier Muddy stream channels and associated topography.

Although the oil pools in the Muddy were a bonus, the discovery of the stratigraphic "Dakota" accumulation confirmed the stratigraphic concept of the prospect and helped shift attention in Wyoming to the potential of stratigraphic oil accumulations at a time when "sheepherder" anticlines were still the vogue.