In the case of Wall et al. v. Parrot Silver & Copper Company et al., 1916, the United States Supreme Court was tasked with deciding on a dispute over water rights in Montana between two mining companies: The Parrot Silver and Copper Company (Parrot) and Boston & Montana Consolidated Copper and Silver Mining Company (Boston). Both companies had been using water from the same source for their operations, but when Boston began to use more than its share, it caused harm to Parrott's operation. As such, Parrott sued for damages and an injunction against Boston’s excessive use of water. The lower court ruled in favor of Parrott; however, this decision was reversed by the state supreme court which held that both parties were entitled to reasonable use of water without regard to prior appropriation or usage. This led to an appeal at the US Supreme Court. The US Supreme Court upheld the ruling made by Montana's highest court stating that under riparian law applicable in some states like Montana - all owners along a body of water have equal rights regardless if one party used it first or has used it longer.

In the dissenting opinion for Wall et al. v. Parrot Silver & Copper Company et al., Justice Holmes disagreed with the majority's ruling that a Montana state law was unconstitutional because it interfered with interstate commerce. He argued that states should have the right to regulate businesses within their borders, even if those businesses also operate in other states. Furthermore, he contended that this particular law did not discriminate against out-of-state companies or impede interstate commerce but merely sought to protect workers' rights and safety by regulating mining operations within Montana's jurisdiction. Therefore, he believed it fell under the purview of state police power rather than federal control over trade between states.