Water Resources Division, U.S. Geological Survey 1967 A slice of geologic history is exposed to view in the Denver, Colorado area. Denver is situated on the High Plains near the east front of the Rocky Mountains. As one travels westward from Denver toward the mountains, successively older rocks are crossed from the geologically young rocks of the High Plains and the South Platte River valley to the older rocks of the foothills and the ancient rocks of the mountains. Thus, within a few miles,the journey turns back the pages of time in a lifesized textbook that vividly illustrates the geologic events that shaped the landscape. application/pdf 10.3133/70039249 en U.S. Government Printing Office Mountains and plains Denver's geologic setting reports