From sweeping prairie to rugged mountains, the Cucharas Valley is a geological panorama. Origins of these landmarks vary, and are grand examples of prehistoric eras. For example, the Spanish Peaks were masses of molten igneous rock which pushed toward the surface but never reached it. The Sangre de Cristos were formed by glaciers.
When the Peaks were formed, magma also surged upward into cracks in the ground and hardened. Over time, the softer sediments surrounding the hardened magma wore away, leaving giant walls called dikes.
These dikes radiate from the Peaks like spoke in a wheel, and vary in length from a few hundred feet to over 14 miles. Many are seen along Highway 12, the most prominent being Devil's Stairsteps and Profile Rock.
South of La Veta is Goemmer's Butte, which is a volcanic plug; although the beginnings of a volcano, it never reached the surface and erupted.
Further south, Highway 12 goes through a gap in the Dakota Wall - a sandstone formation running from Mexico to Canada and nicknamed the "backbone of the Rockies."