The U.S. Supreme Court case Wilshire Oil Co., Inc. et al. v United States et al., 1934, revolved around the issue of oil extraction from federal lands in California by private companies without proper leasing or payment to the government for extracted resources. The plaintiffs, Wilshire Oil Company and others, argued that they had rights to extract oil based on Spanish land grants predating American control over California territory after the Mexican-American War (1846-48). However, these claims were rejected as it was determined that such rights did not extend to mineral resources beneath the surface of granted lands unless explicitly stated in original deeds - which was not found to be true in this case. Therefore, any extractions made by these companies were deemed illegal under existing laws governing resource extraction on public lands at that time; specifically those outlined within a 1920 law known as Mineral Leasing Act.

The dissenting opinion in the case of Wilshire Oil Co., Inc. et al. v. United States et al., 1934, argued that the majority's decision was a misinterpretation of Congress' intent when it passed the Mineral Leasing Act of 1920 and its amendments in 1926 and 1931. The dissent contended that these laws were designed to encourage private development of oil resources on public lands by granting leases to those who discovered oil, not to allow government agencies like the Navy Department to monopolize such resources for their exclusive use without offering them up for competitive bidding as required by law. They believed this interpretation would discourage future exploration and production efforts by private companies, contrary to what Congress intended with its legislation.