In the 1907 case of Winters v. The United States, the U.S. Supreme Court ruled in favor of Native American rights to water resources on reservation lands. The Fort Belknap Indian Reservation in Montana had been established by a treaty between the federal government and two tribes, but did not explicitly grant water rights to them. When non-Native settlers began diverting water from a river running through the reservation for their own use, tribal members sued for infringement of their implied right to use that resource under the terms of their agreement with Washington D.C.. In its decision, known as "the Winters Doctrine", the court held that when Congress reserves land (in this case for an Indian Reservation), it also reserves sufficient water to fulfill the purposes of that reservation thereby ensuring access and control over necessary resources.

In the dissenting opinion for Winters v. United States, Justice Brewer argued that the majority's interpretation of the treaty was incorrect and overly broad. He contended that there was no explicit provision in the treaty granting water rights to Native American tribes, and therefore it should not be inferred by implication. Furthermore, he pointed out that at the time of signing, both parties were aware of irrigation practices but did not include any specific provisions regarding this in their agreement. Therefore, according to him, if they had intended to grant such extensive water rights they would have done so explicitly within the text of the treaty itself rather than leaving it up to future judicial interpretation.