Geologic Maps

Tracy Vallier has geologically mapped, and compiled data gathered by other geologists, parts of twenty-six 7.5-Minute USGS quadrangles, each of which incorporates approximately fifty square miles. Eighteen of the quadrangles extend along the Snake River from the Oxbow on the south to the Washington-Oregon border. These eighteen quadrangles from south to north (some are side by side) are the following: Oxbow, Homestead, Cuprum, White Mountain, Puderbaugh Ridge, Squirrel Prairie, Hat Point, He Devil, Old Timer Mountain, Kirkwood Creek, Temperance Creek, Grave point, Lord Flat, Wolf Creek, Cactus Mountain, Deadhorse Ridge, Wapshilla Creek, and Jim Creek Butte. Eight bordering quadrangles, where some mapping has been done, are Posy Valley, Halfway, Deadman Point, Duck Creek, Gumboot Butte, Rattlesnake Ridge, Kessler Creek, and Heavens Gate.

Each quadrangle requires additional work, but Tracy is familiar with the rocks and can finish all of part of a particular map if funds and an assistant are available. As he completes the maps (hand drafted, lettered, and colored), they will be put on this web site for sale. The Oxbow quadrangle is finished, except for a final legend, and the Cuprum and Homestead quadrangles can be finished with minimal fieldwork and a year for final compilation and legend. Contact Tracy if you either have specific areas to map or are interested in purchasing the completed maps.

Logistics caused by a general absence of roads and physical challenges forced by the rugged landscape make geological work slow and difficult. High summer temperatures, up to 115 degrees in the bottom parts of Hells Canyon, compound difficulties. All geologic maps are “works-in-progress.” They are never really completed. Some areas within quadrangle maps, by virtue of logistics, changing interpretations, and stratigraphic or structural complexities are reconnaissance level only. Other areas are mapped in detail.