This paper looks at economic factors and water rights quantification on 95 Native American reservations economies in the western United States (U.S.). The study looks at the issues in two parts: (1) the characteristics of reservations quantifying their water rights compared to those who do not and (2) the effects of water rights quantification on reservation economic characteristics. Data was compiled from the U.S. Census Bureau, USDA, water specialists, court decrees, news articles, and scholarly papers. Results found that tribes who operate casinos and have higher revenues from agricultural goods are more likely to have quantified their water rights. Tribes with quantified water rights also had increased income levels. This study can help tribes design policies to create sustainable water management policies and economies on tribal reservations.