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.
[Illustration: 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)]