How have the laws governing land use been interpreted and interpreted?

By reading all the pertinent Congressional legislation together insofar as it lays out a general system of land laws,²⁷ we find no indication that we should depart from the principle of statutory construction by which repeal by implication is not favored. Wherever possible, effect should be given to both earlier and later statutes; repeal can only be implied when the new statute(s) is clearly repugnant, in words or purpose, to the old statute(s). There can be no repeal unless the intention of the legislative body to repeal is clear. United States v. Borden Co., 308 U.S. 188, 198-199, 60 S.Ct. 182, 84 L.Ed. 181 (1939).