Meander lines

Lines run in surveying particular portions of the public lands which border on navigable rivers, not as boundaries of the tract, but for the purpose of defining the sinuosities of the banks of the stream, and as the means of ascertaining the quantity of land in the fraction subject to sale, and which is to be paid for by the purchaser. In preparing the official plat from the field notes, the meander line is represented as the border line of the stream, and shows that the water-course, and not the meander line as naturally run on the ground, is the boundary.

St. Paul & P. R. Co., v. Schurmeier, 7 Wall. 286, 19 L. Ed. 74; Niles v. Cedar Point Club, 175 U. S. 300 , 20 Sup. Ct. 124, 44 In Ed. 171.