Sangre de Cristo Range and Spanish Peaks
The Sangre de Cristo Mountains are visible from many parts of southeastern Colorado as a jagged, sawtoothed, snow-crested ridge on the western skyline. They extend about 150 miles from the Arkansas River near Salida southward into New Mexico.
Few mountain ranges form so impassable a barrier as the Sangre de Cristos. Only at La Veta Pass does a highway cross the range. However, old wagon roads, passable now by jeep or on foot, once existed across Hayden, Music, Mosca, and Whiskey Creek Passes.
Often no more than twenty miles wide, the central portion of the range is composed largely of red Late Paleozoic sediments like those exposed in the Garden of the Gods and Red Rocks Park. These rocks are intricately folded and faulted, but not metamorphosed. They include sandstones, shale, [conglomerates], and fossil-bearing limestones. The northern end of the range is formed of Precambrian igneous and metamorphic rocks.
Just west of La Veta Pass, Sierra Blanca stands as an outpost of the range where its continuity is interrupted and its structure changed. Huge blocks of Precambrian [granite] were here pushed upward and thrust westward to form a cluster of peaks, several of which are over 14,000 feet in elevation.
Many prominent rock [glaciers] are present in the Sangre de Cristo Mountains. They are composed of fragments of rock, lubricated by snow and ice, creeping almost imperceptibly down the steep flanks of the high peaks. One of these rock glaciers can be seen on the slope of Mt. Mestas east of La Veta Pass; others are visible from Great Sand Dunes National Monument.
South of La Veta Pass, an igneous intrusion along the axis of the range changes the character of the Sangre de Cristos. This intrusion is harder and has weathered more slowly than the rest of the range, and forms a group of prominent peaks known as the Culebra Range.
On the west flank of the Sangre de Cristo Range, east of Villa Grove, a prominent iron-mineralized area can be seen. Here the ghost mine of Orient marks the site where iron ores were mined in the early days of the Colorado Fuel and Iron Company. Nearby, an abrupt terrace along the edge of the valley marks the position of a [fault]. Recent gravels are involved in this fault, indicating that movement has taken place here within the last few hundred years. A number of hot springs occur along the base of the mountains nearby.
The Spanish Peaks, not structurally related to the Sangre de Cristos, are visible from La Veta Pass highway. These two peaks represent a pair of Cenozoic volcanoes, now deeply eroded and much reduced from their former height. Numerous [dikes] radiating from the bases of these peaks represent fissures which were filled with [lava] as the peaks formed.
The Great Sand Dunes, close to the Sangre de Cristo Mountains north of Sierra Blanca, are discussed in Chapter II in the section on the [Quaternary Period].
Spanish Peaks, south of Colorado Springs and southwest of Walsenburg, are twin mountains of volcanic and intrusive rock, the roots of Tertiary volcanoes greatly worn down and reshaped by erosion. This view looks southeast from near La Veta Pass, on U.S. Highway 160. (Jack Rathbone photo)