As the Nation’s principal conservation agency, the Department of the Interior has basic responsibilities for water, fish, wildlife, mineral, land, park, and recreational resources. Indian and Territorial affairs are other major concerns of America’s “Department of Natural Resources.” The Department works to assure the wisest choice in managing all our resources so each will make its full contribution to a better United States—now and in the future. U.S. DEPARTMENT OF THE INTERIOR NATIONAL PARK SERVICE ★ U. S. GOVERNMENT PRINTING OFFICE: 1970 O - 389-735 [Illustration: Locomotive.] [Illustration: Book Jacket.] * * * * * * Transcriber’s note: —A few typographical errors were corrected without comment. —Retained publication information from the printed edition. —Moved some captions nearer to the corresponding pictures, and removed (or adjusted) references to picture location in the printed book.