OF-06-06 Geologic Map of the Palmer Lake Quadrangle, El Paso County, Colorado

The Rampart Range rises abruptly west of the Rampart Range Fault, which transects the quadrangle north to south. East of the fault zone is the comparatively subdued topography of the Colorado Piedmont. Elevation within the quadrangle ranges from roughly 6,800 feet along Hay Creek and Beaver Creek in the southeastern part of the quadrangle to 9,378 feet on an unnamed knoll along the Schubarth Trail in the southwestern part of the quadrangle. Mount Herman, which rises to 9,063 feet along the range front, is the most prominent peak in the quadrangle as viewed from the flatter and more populated eastern part of the mapped area and Interstate 25. Several creeks and ephemeral streams that originate in the Rampart Range flow from west to east across the quadrangle and are part of the Arkansas River drainage basin. The principal streams and drainages within the quadrangle are, from north to south, Monument Creek, North Monument Creek, North and South Beaver Creeks, Hay Creek, Deadmans Creek, and Goat Camp Creek. Most of the forested land in the Rampart Range is administered by the U.S. Forest Service (Pike Peak Ranger District, Pike National Forest). The flatter land in the eastern one third of the quadrangle, aside from the U.S. Air Force Academy, is mostly privately owned.

The oldest rocks exposed in the Palmer Lake quadrangle are granitic rocks of the late Mesoproterozoic Pikes Peak batholith, which forms the Rampart Range. Rocks of the batholith are faulted against Laramide-age synorogenic sedimentary rocks of the Dawson Formation along the Rampart Range Fault, a major north-south reverse fault that separates the Rampart Range from the Denver Basin. The fault also serves as the physiographic demarcation between the Colorado Piedmont and the Rampart Range physiographic provinces.