In the United States v. Dann et al., 1984, the Supreme Court ruled against Mary and Carrie Dann, two Western Shoshone sisters who claimed that they held title to a large area of land in Nevada based on aboriginal possession. The U.S. government argued that it had gained control over this territory through a process known as "gradual encroachment," which involved slowly taking over lands traditionally used by indigenous peoples for farming or hunting without any formal treaty or purchase agreement. The court found in favor of the government, stating that even though no specific act of Congress had extinguished the tribe's rights to these lands, their claim was invalidated due to payment made by Indian Claims Commission for those lands in 1979. This ruling has been criticized for its potential implications regarding native land rights and sovereignty.

In the dissenting opinion for United States v. Dann et al., Justice Brennan, joined by Justice Marshall, disagreed with the majority's interpretation of Public Law 85-547. They argued that this law did not extinguish Western Shoshone title to their ancestral lands but merely provided compensation for past damages and infringements on their rights. The dissent pointed out that Congress had never explicitly terminated Western Shoshone title in clear and unambiguous terms as required by precedent. Furthermore, they noted that even if one were to accept the majority's view that payment from a judgment fund equated to termination of land rights (which they disputed), such payment had not actually occurred because most tribal members refused it due to ongoing disputes over land ownership. Therefore, according to the dissenters' interpretation of both statutory text and legislative history, along with principles of Indian law requiring any ambiguities be resolved in favor of Native American tribes, Mary and Carrie Dann still retained grazing rights on public lands under dispute.