The Wasatch Mountains mark a major zone of structural transition in the Sevier-Laramide orogenic belt. A regional system of frontal and sidewall thrust-fault ramps developed in the overthrust belt beneath the western edge of the Wasatch Mountains during the Late Cretaceous. The basal decollement stepped upsection to the east, from a depth of about 15 km in Proterozoic strata and crystalline basement in the region west of the Wasatch Mountains, to a level in lower Paleozoic and Mesozoic strata toward the east. This ramp system strongly influenced the geometry of the overlying allochthons as they were transported eastward toward the foreland. Large hanging wall folds formed during formation of frontal and sidewall ramps (fault propagation folds) and during subsequent transp rt of thrust sheets over the underlying ramps. Lateral boundaries of the Absaroka and Charleston allochthons formed above major sidewall ramp systems that extended into the crystalline basement. The Uinta arch is a large, north-vergent anti-clinorium in the Wasatch Mountains that forms the westward continuation of the Uinta Mountain structure. Structurally, the arch lies in the southernmost part of the hanging wall of the early Paleocene Hogsback thrust system. The arch began to form during latest Cretaceous and early Paleocene time as eastward movement on the Hogsback decollement was transferred onto a south-dipping thrust ramp beneath the Uinta arch. The anticlinal structure of the Uinta arch formed in response to distortion of the hanging wall above the fault ramp and involved a compo ent of northward-directed crustal shortening in addition to the sinistral slip. Uplift of the Uinta Mountains occurred at the same time and may reflect regional displacement of the crust along the south-dipping fault system. Uplift and faulting in the Uinta Mountains continued throughout the Paleocene and Eocene, postdating movement on the Hogsback thrust.

Fluvial strata of the Currant Creek, Uinta, and Duchesne River formations (Late Cretaceous-Paleocene in age) record tectonism in the central Rocky Mountains. They are related to separate episodes of regional uplift in the Wasatch Mountains and Uinta Mountains and in western and southwestern Colorado. The Currant Creek Formation of Maestrichtian-Paleocene(?) age documents major tectonism in the north-central Utah overthrust belt by its thick conglomerate and sandstone units deposited in coalescing alluvial fans. Conglomerate clast composition and southerly paleocurrent directions in the upper part of the formation indicate uplift of the western end of the Uinta arch. The Uinta Formation was derived from volcanic terrains exposed to the east and deposited within the fluvial and lacustri e facies of Lake Uinta. Sediment of the Eocene-Oligocene Duchesne River Formation was derived from the Uinta Mountains. Conglomerate and sandstone is rich in sedimentary and metasedimentary rock fragments. Southward-directed fluvial deposition occurred within the Uinta Basin in response to Eocene-early Oligocene uplift and faulting of the Uinta Mountains.