OF-18-03 Geologic Map of the Lands End Quadrangle, Mesa County, Colorado

Extending previous CGS mapping efforts on the Grand Mesa in the Western Slope region the state, this publication describes the geology of this 7.5-minute quadrangle located 30 km south of De Beque and immediately east of Palisade, Colorado. Includes GIS data and two PDF plates. Digital ZIP download. OF-18-03D

From the Resources section:

The Lands End quadrangle includes the Palisade Lobe of Grand Mesa. The upper watersheds along its high-elevation flanks are important water resources for local communities and irrigated agricultural lands to the west. The mesa-top reservoirs and Whitewater, Cottonwood, Rapid, and Kannah creek watersheds provide irrigation water and vital drink ing water supplies to the Town of Palisade and City of Grand Junction. In the broad Mesa Creek valley to the north, the many water w ells for both human and livestock consumption produce water from the thick unconsolidated surficial deposits that extend upwards to the higher-elevation areas where seasonal snow melt infiltrates and recharges the aquifers. The underlying rock formations are not appreciable water producers.

Potential geologic hazards in the map area are primarily the risks of ground movement. Landslides are ubiquitous to almost all areas of the map area below the GMVF rim. Except for private lands along State Highway 65 and the ski area, most land within mapped landslide areas is vacant, either public lands or private ranch land. Areas of mapped landslides and earthflows should be considered susceptible to future ground movements. Careful geological and geotechnical investigations should be completed for any site within mapped landslide areas if there are land-use changes and occupied structures are planned. Those investigations would also be warranted for prospective buyers of real estate within mapped landslides, especially if existing residential structures are included. Earth flows and debris-flow /flash flooding can have long runouts so careful planning and siting of structures is also important in the vicinity of creek floors and drainage swales. This map only shows existing landslides and earthflows, and does not reflect future risk or reoccurrence intervals. Future landsliding could occur in any susceptible area along the flanks of Grand Mesa. Those ground movements can range from slow near-imperceptible creep to dangerous, potentially catastrophic, very high velocity, rock avalanche-type earthflows.