In Grosfield et al. v. United States, 1927, the Supreme Court dealt with a dispute over land ownership in Montana between private parties and the federal government. The plaintiffs claimed that they had acquired title to certain lands through purchase from railroad companies who were granted these lands by an act of Congress in 1864. However, the U.S Government argued that it still owned those lands because they fell within an Indian reservation created by treaties in 1855 and 1868 before the Congressional Act was passed. The court ruled against Grosfield and his co-plaintiffs stating that when there is a conflict between a treaty made with Native American tribes and subsequent legislation, priority should be given to earlier treaties unless Congress has explicitly abrogated them or changed their terms clearly and unambiguously. Therefore, since neither of these conditions were met here - as no clear intent could be found on part of Congress to deprive Indians of their rights under previous treaties while passing this Act - it was held that these disputed lands remained part of Indian Reservation despite being included within limits defined for grant purposes under said Act.

In the dissenting opinion for Grosfield et al. v. United States, Justice Holmes disagreed with the majority's interpretation of the law regarding land ownership and mineral rights in Montana. He argued that under state law, a person who owns surface rights to a piece of property also has claim to any minerals found beneath it unless explicitly stated otherwise in their deed or lease agreement. The majority ruled that because Congress had not specifically granted mineral rights to homesteaders when they passed legislation opening up public lands for settlement, those rights remained with the federal government by default. However, Holmes contended this was an overly narrow reading of Congressional intent and unfairly penalized settlers who were unaware they needed to secure separate mineral claims on their own properties.