Loew, O., 1875, Report upon mineralogical, agricultural, and chemical conditions observed in portions of Colorado, New Mexico, and Arizona, in 1873, Part VI., in U.S. Army Engineer Department, Report upon geographical and geological explorations and surveys west of the one hundreth meridian, in charge of First Lieut. Geo. M. Wheeler, V. 3, Geology: Washington, D.C., U.S. Government Printing Office, p. 569-661.