Mississippi River. Annual report upon operating snag boats and dredge boats on upper Mississippi River, improvement of Mississippi River between Missouri River and St. Paul, Minn., and of harbors at Moline, Ill., and La Crosse, Wis., operating and care of Galena River improvement, and of Illinois and Mississippi Canal around lower rapids of Rock River at Milan, Ill., in charge of Jas. L. Lusk and C. S. Riché; app. Y of report of chief, 1950.