Summary of Content: Title continues ”being Chapter VI and Appendix E of the Report of Lieut. Henry L. Abbot, Corps of Topographical Engineers, upon Explorations for a Railroad Route from the Sacramento Valley to the Columbia River made by Lieut. L.S. Williamson, Corps of Topographical Engineers, assisted by Lieut. Henry L. Abbot, Corps of Topographical Engineers.” Presentation copy signed on cover with an inscription by Henry L. Abbot to Edwin Hale Abbot. Part of the series, ”Explorations and survey for a railroad route from the Mississippi River to the Pacific Ocean. War Department.” Original yellow covers. Printed by the Government Printing Office.