Excerpt from Preliminary Field Report of the United States Geological Survey of Colorado and New Mexico, 1869 Sir: In accordance with your instructions dated Washington, April 1, 1869, I have the honor to transmit my preliminary field report of the United States geological survey of Colorado and New Mexico, conducted by me, under your direction, during the past season. A portion of your instructions is as follows: "You will proceed to the field of your labors as soon as the necessary arrangements can be made and the season will permit, and your attention will be especially directed to the geological, mineralogical and agricultural resources of the Territories herein designated; you will be required to ascertain the age, order of succession, relative position, dip, and comparative thickness of the different strata and geological formations, and examine with care all the beds, veins, and other deposits, of ores, coals, clays, marls, peat, and other mineral substances, as well as the fossil remains of the different formations; and you will also make full collections in geology, mineralogy, and paleontology, to illustrate your notes taken in the field." In accordance with the above instructions I proceeded to Cheyenne, Wyoming Territory, where my preparations and outfit were made. My assistants were selected as follows: 1. James Stevenson, managing director and general assistant. 2. Henry W. Elliott, artist. 3. Rev. Cyrus Thomas, entomologist and botanist. 4. Persifer Frazer, jr., mining engineer and metallurgist. 5. E. C. Carrington, jr., zoologist. 6. B. H. Cheever, jr., general assistant. Five men were also employed, three of them as teamsters, one as laborer, and the other one as cook. As soon as my preparations were completed, my field labors commenced, June 29, at Cheyenne. Limited somewhat as to time and means, I arranged my plans so as to cover as much ground as possible and secure the greatest amount of geological information. On the plains the geological structure is very simple, and frequently over large areas the basis rocks are concealed by superficial deposits. It seemed best, therefore, to make my examinations southward along the eastern base of the Rocky Mountains for the purpose of studying the upheaved ridges, or "hog backs," as they are called in this country. These ridges afford peculiar facilities for working out the geological structure of the country. Indeed, they are like the pages of an open book upon which the geologist can read what the Creator has written upon each formation known in the country from the granite mass that forms the nucleus of the loftiest mountain range to the most recent tertiary formation inclusive. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.