Text this: South Platte River and its tributaries, Colorado, Wyoming, and Nebraska. Letter from the Secretary of the Army transmitting a letter from the Chief of Engineers, United States Army, dated July 2, 1946, submitting a report, together with accompanying papers and illustrations, on a preliminary examination and survey of South Platte River and its tributaries, Colorado, Wyoming, and Nebraska, authorized by the Flood Control Act approved on August 11, 1939.