Chapter 7.2, Page 1 of 4

The Wet Mountain Valley and Huerfano Park are located in south-central Colorado in southwestern Fremont, western Custer, and northwestern Huerfano counties between the Sangre de Cristo Mountains on the west and the Wet Mountians on the east. Both these intermontane basins contain thick Tertiary-age, basin-fill sediments. These two areas fall within and are under the administration of Water Division 2 of the Colorado Division of Water Resources (Figure 7.2-1).

Figure 7.2-1 Location and extent of the Wet Mountain Valley and Huerfano Park, showing the distribution of permitted water wells. (Click image to zoom .4MB)

The Promontory Divide forms the boundary between the Wet Mountain Valley and Huerfano Park, as well as Custer and Huerfano counties. The two areas are discussed together because their basins are adjoining and their geology and hydrology are similar. The basin-fill deposits of the Wet Mountain Valley cover an area of approximately 230 square miles. Huerfano Park lies directly southeast of the Wet Mountain Valley and is underlain by many of the same aquifers. Land use in this area is primarily agriculture, rangeland, or forest. The area is sparsely populated with an average population density of approximately five residents per square mile.

Surface water streams and creeks in the Wet Mountain Valley flow north to the Arkansas River, while those in Huerfano Park generally flow south toward the Huerfano River which is itself tributary to the Arkansas. Near-surface rocks in the Wet Mountain Valley and Huerfano Park range in age from Precambrian to recent, but the primary aquifers are basin-fill deposits of Tertiary and Quaternary age. In both areas, these deposits exceed 6,000 feet in thickness. A generalized geologic cross-section through Huerfano Park is shown as Figure 7.2-2.

Figure 7.2-2 Generalized geologic cross section through Huerfano Park. Modified from Briggs and Goddard, 1956. (Click image to zoom .5MB)

Chapter 7.2, Page 1 of 4