Hydrodynamic flow in the Muddy aquifer system is generally downdip from the outcrop westward toward the basin with an average gradient of 50 ft/mi (10 m/km). Flow patterns are controlled largely by the distribution of porous sandstone so that the regional patterns of flow tend to reflect the total thickness of the Muddy aquifer. However, local potentiometric highs appear to represent isolated areas of high pressure and downward flow from Mowry source rock to the Muddy aquifer.

Muddy sandstones are lenticular and form stratigraphic traps, but oil columns are determined largely by hydrodynamic flow. For example, calculations of oil column suggest that flow accounts for 130 ft (40 m) of the total 150 ft (46 m) of oil column at Recluse field; for 208 ft (63 m) of the total 250 ft (76 m) at Gas Draw field; and 429 ft (150 m) of the total 500 ft (168 m) at Bell Creek field. Larger oil columns are the result of vertical flow. For example, a potentiometric high of 6000 ft (1830 m) occurs at Kitty field, about 4000 ft (1220 m) in excess of the expected hydrostatic head, and the vertical pressure gradient probably accounts for a large part of the total 700 ft (214 m) of oil column.