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23 and county laws as discussed in Section 1.1, Regulatory Framework. 2.2 Geologic Context In 1985 a study was completed by Fox consultants that provided a detailed summary of the geologic setting of the Dowe Flats area for the purpose of assisting in the planning and execution of subsurface explorations and engineering investigations in this area. This study addresses regional and local bedrock stratig- raphy and structural geology. The scope of the Fox report included compilation of existing geologic data through August 1989 and interpretation of these data aided by aerial photography interpretation and site reconnaissance (Fox 1985). The Dowe Flats area is in the Foothills Belt, a transition zone between the Front Range physiographic province to the West and the Denver Basin physiographic province to the east. The Front Range, which is the eastern most range of the Southern Rocky Mountains, begins on the northern side of the Arkansas River in southern Colorado and extends northward for approximately 185 miles to the Wyoming border. The range varies from 25 to 45 miles in width (BOOS and Boos, 1957), and was formed by vertical uplift and subsequent erosion of the sedimentary strata to expose the Precambrian core. Remnants of the original sedimentary cover, now present as truncated sedimentary rocks along the uplift flank, are tilted by drag along the uplift boundaries. The more resistant tilted rocks, generally sandstones and some carbonates, form linear hogbacks that parallel the mountain front. The less resistant shales have been eroded away to form linear valleys between the hogbacks. This linear system of valleys and ridges is present along most of the eastern Front Range boundary. The Foothills Belt is a transitional area about five to 10 miles wide between these two major physiographic provinces. The sedimentary beds adjacent to the Precambrian mountain front are steeply dippling and occasionally overturned. The dip