The Farncomb et al. v. City and County of Denver et al., 1919, was a case that revolved around the issue of taxation on mining claims in Colorado. The plaintiffs, owners of unpatented mining claims in Clear Creek County, argued that their properties were being unfairly taxed by the city and county of Denver at an excessive rate compared to other real estate property within the same jurisdiction. They contended this violated their rights under the Fourteenth Amendment's Equal Protection Clause as they were not treated equally with other taxpayers. However, the Supreme Court ruled against them stating that there was no violation because different types of property could be subjected to different methods or rates of taxation without infriting upon constitutional equal protection principles so long as it is not arbitrary or discriminatory. The court held that due to its unique nature and speculative value, taxing mining claim properties differently from ordinary real estate did not constitute unequal treatment.

In the dissenting opinion for Farncomb et al. v. City and County of Denver et al., Justice McReynolds argued that the majority's decision to uphold a tax assessment on mining claims was unconstitutional, as it violated due process rights under the Fourteenth Amendment. He contended that this taxation method unfairly burdened mine owners by taxing them based on potential future profits rather than current value or income from their properties. This speculative approach, he believed, could lead to excessive taxation and financial hardship for mine owners who may not realize these projected earnings due to unpredictable market conditions or other factors beyond their control. Furthermore, he criticized the majority's reliance on previous case law upholding similar assessments in agricultural contexts because mining operations are inherently different and riskier ventures with unique economic challenges.