In the 1893 U.S. Supreme Court case of Aztec Mining Company v. Ripley, the court examined a dispute over mining rights in Colorado between two companies: The Aztec Mining Company and Ripley's company. The conflict arose when both parties claimed ownership of valuable mineral deposits found within overlapping land claims. The lower courts ruled in favor of Ripley, asserting that his claim was valid because he had made significant improvements to the land before Aztec staked their claim. The Supreme Court upheld this decision, stating that under federal law (the General Mining Act), priority is given to those who first discover minerals on public lands and then make improvements or perform labor on these lands with intent to possess them for mining purposes - even if they have not yet formally registered their claims with local authorities. This ruling reinforced the principle known as "prior appropriation," which holds that rights are determined by whoever first uses a resource rather than who owns property containing it.

In the dissenting opinion for Aztec Mining Company v. Ripley, it was argued that the majority's decision to uphold a lower court ruling in favor of Ripley was incorrect due to an erroneous interpretation of mining law. The dissenting justices believed that the plaintiff, Aztec Mining Company, had established its right to mine on disputed land under federal mining laws and regulations. They contended that these laws were designed specifically to encourage exploration and development of mineral resources by granting exclusive rights to those who first discover valuable minerals on public lands. Therefore, they asserted that once such discovery is made and properly recorded as per legal requirements, no subsequent locator can claim any part of this discovered lode without proving their own independent discovery within it - something which defendant Ripley failed to do according to them. Thus, they disagreed with the majority's view which seemed more inclined towards protecting individual property rights over promoting resource development.