Detailed geologic mapping along Teton Pass, southwest of Jackson, Wyoming, has led to a reinterpretation of the spatial and sequential relations between the Paleocene-Eocene detached Jackson thrust and foreland Cache Creek thrust in that area. Structural evidence from both thrust sheets shows that where the two faults overlap, the Jackson thrust sheet was overridden by foreland rocks during southwestward movement along the Cache Creek thrust. Movement of the Cache Creek thrust sheet caused several anticlines along the leading edge of the Jackson thrust sheet to overturn to the southwest. Anomalous southwestward overturned folds elsewhere in the northern Snake River range may also be a result of this deformation. Continued movement of the Cache Creek thrust sheet sharply o erturned the anticline on the leading edge of the Cache Creek thrust to the southwest and broke it along two major reverse faults that die out westward into an overturned anticline.

Cretaceous rocks form a common footwall of the Jackson and Cache Creek thrusts. On Teton Pass these rocks, squeezed up between the two faults, are nearly vertical and very broken. Seismic studies oriented at right angles to the apparent movement of the thrusts are necessary to determine the subsurface structure of the footwall, thrust belt, and foreland rocks in this overlap area from west of Teton basin, Idaho, to Hoback basin, Wyoming. Although the rocks on Teton Pass appear to be too deformed to produce oil and gas, suitable prospects may exist where the interaction of thrust belt and foreland deformation was less intense.

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