South West pass of the Mississippi River

Scale 1:20,000.
LC Civil War Maps (2nd ed.), 36.1
From its Report of the Superintendent of the Coast Survey, showing the progress of the survey during the year 1862 (Washington, Government Printing Office, 1864). Map 36.
At head of title: U.S. Coast Surveys, A. D. Bache, Superintendent.
"No. 36" in the upper left corner.
Description derived from published bibliography.
Available also through the Library of Congress web site as raster image.