Around 10,000 to 15,000 feet of sediment covered the old highland surface in the Mesozoic and early Cenozoic.

During the Oligocene, the Colorado mineral belt began to form with the intrusion of two batholiths.

One of these batholiths rose sufficiently near the surface, enough to feed volcanoes in the West Elk and San Juan Mountains.

The resulting volcanic pile has been subjected to intermittent, occasional uplift as well as being shaped by water and ice.

Mineral deposits are somewhat scarce in the surrounding area of the peak, but bituminous coal has been mined on the northern and eastern flanks.