11. Topographic quadrangle maps. Illinois, Bethalto quadrangle, lat. 38°52′30″-39°, long. 90°-90°07′30″. Scale 1:24,000, contour Interval 10 ft. n. p. Bookmark Corporate/Agency Authors: Geological Survey and Interior Dept. Publisher: Geological Survey Date: edition of 1949 SuDoc number: I 10.12:12 B 465/949