Extending the CGS mapping efforts in the far northwest corner of the state, this publication describes the geology of this 7.5-minute quadrangle located near Craig, Colorado. CGS staff geologist Peter E. Barkmann, along with Erinn Johnson and William Curtiss completed the field mapping on this project during the summer and fall of 2015 and 2016. Digital ZIP download. OF-16-07D
Excerpted from USGS Open-File Report 79-880:
The Ralph White Lake quadrangle lies in the southern part of the Wyoming Basin physiographic province as defined by Howard and Williams. The quadrangle is approximately 5 miles (8 km) north of the Williams Fork Mountains and 36 miles (58 km) west of the Continental Divide.
Moderate slopes and narrow gulches are dominant throughout most of the quadrangle. Wide flat valleys occur along Fortification Creek in the northwestern part of the quadrangle and along Elkhead Creek and the Yampa River in the southern part of the quadrangle.
Approximately 730 feet (223 m) of relief is present in the Ralph White Lake quadrangle. Altitudes range from about 6,920 feet (2,109 m) in the northeast corner of the quadrangle to slightly less than 6,200 feet (1,890 m) along the Yampa River in the southwestern corner of the quadrangle.
The Yampa River, the major drainage system in the area, flows westward across the southern part of the quadrangle. Fortification Creek flows southward across the northwestern corner of the quadrangle joining the Yampa River at Craig, approximately 2.5 miles (4.0 km) west of the quadrangle. Elkhead Creek, a tributary of the Yampa River, drains the east-central part of the quadrangle. The remainder of the quadrangle is drained by numerous small intermittent creeks which flow mainly in response to snowmelt in the spring. Ralph White Lake is located on Fortification Creek in the northwestern corner of the quadrangle and Leftwich Reservoir lies at the mouth of Boone Gulch in the southwestern part of the quadrangle.