When plate tectonics became the standard model for mountain building processes, the presence of the Rocky Mountains still defied easy explanation. In an attempt to explain the uplift, geologists invoked a novel idea, which remains one of the most attractive theories to explain the Laramide Orogeny.

The theory holds that a pacific plate (the Farallon plate) was subducted underneath North America at a shallow angle. The shear stress exerted at the base of the lithosphere as the plate traveled eastward was enough to push up the Rocky Mountains. The theory has also been invoked to explain the Colorado Mineral Belt, a coeval magmatic providence in the Southern Rocky Mountains, at the edge of the proposed subducted plate.