“ Both courts below found that the lake was navigable. But they treated the question of navigability as one of local law to be determined by applying the rule adopted in Minnesota. We think they applied a wrong standard. Navigability, when asserted as the basis of a right arising under the Constitution of the United States, is necessarily a question of federal law to be determined according to the general rule recognized and applied in the federal courts. ”

“ Bowlby, at pages 49, 57, 58 (14 S.C.t. 548) , the United States early adopted and constantly has adhered to the policy of regarding lands under navigable waters in acquired territory, while under its sole dominion, as held for the ultimate benefit of future states, and so has refrained from making any disposal thereof, save in exceptional instances when impelled to particular disposals by some international duty or public exigency. ”

“ The effect of what was done was to reserve in a general way for the continued occupation of the Indians what remained of their aboriginal territory, and thus it came to be known and recognized as a reservation. Minnesota v. Hitchcock, 185 U.S. 373, 389, 22 S.C.t. 650, 46 L. Ed. 954. There was nothing in this which even approaches a grant of rights in lands underlying navigable waters; nor anything evincing a purpose to depart from the established policy, before stated, of treating such lands as held for the benefit of the future state. ”

“ Thereafter the lands in the vicinity of Mud Lake were surveyed and platted in the usual way; the lake being meandered and represented on the plat as a lake. The tracts bordering on the lake were classified as agricultural, opened to homestead entry, and disposed of to homestead settlers; patents being issued in due course. The defendants now own and hold these tracts under the patents. After the homestead entries were allowed, and after most of them were carried to patent, the lake was drained and its bed made bare by a public ditch constructed under the drainage laws of the state. ”

“ Economy Light & Power Co. v. United States, 256 U.S. 113, 121, 41 S.C.t. 409, 65 L. Ed. 847; Oklahoma v. Texas, 258 U.S. 574, 586, 42 S.C.t. 406, 66 L. Ed. 771; Brewer-Elliott Oil & Gas Co. v. United States, supra, p. 86 (43 S.C.t. 60) . ”