OF-14-15 Geologic Map of the Hotchkiss Quadrangle, Delta County, Colorado


The purpose of this report is to describe the geology, mineral and ground-water resources, and geologic hazards of this 7.5-minute quadrangle located east of Delta on the Western Slope of Colorado. CGS staff geologist David Noe and field assistant Emma Rodgers completed the field work on this project during the summer of 2012. The geologic map plates and the Author’s Notes report were created using data from field maps, structural measurements, photographs, and field notes generated by the investigators. Digital ZIP download. OF-14-15D

From the Author’s Notes:

The Hotchkiss 7.5-minute quadrangle is located in Delta County, Colorado. It includes the town of Hotchkiss. The region is known for its orchards, vineyards, and organic agriculture. The valley of the North Fork Gunnison River (known locally as the North Fork River) bisects the quadrangle from northeast to southwest. The lowest elevation (5,210 ft) is where the river exits to the west. To the north of the river are numerous gravel-capped mesas and shale peaks, dissected by tributary streams that drain the southern slopes of Grand Mesa. The highest elevation is on Oak Mesa at the northwestern corner (7,730 ft). To the south of the river is an area of shale badlands known as the “Hotchkiss adobes,” “the adobe hills,” or simply, “the adobes.” A number of low mesas are scattered across the eastern part of the badlands. Shale slopes flank the tributary valleys and mesas throughout the quadrangle. Scenic Mesa, at the toe of the resistant dip slope of the Gunnison Uplift, is in the far southwest corner of the quadrangle.