求助：OG13第13篇

ChenLuAda

In Wintersv. United States(1908), the Supreme Court held that the right to use waters flowing through or adjacent to the Fort Belknap Indian Reservation was reserved to American Indians by the treaty establishing the reservation.Althoughthis treaty did not mention water rights。
想问下the right to use waters 不就是water right 吗？怎么能说没有mention呢？
reservation是什么意思？