Abandoned Uranium Mines (AUM) are the main source of anthropogenic uranium (U) contamination on the Navajo Nation [1]. In parts of the Navajo Nation, AUMs have altered the environment negatively and impacted the lives and health of people since the 1950s [2]. Main routes of U exposure are the ingestion of contaminated drinking water, ingestion of contaminated food stuffs, and inhalation of dust blown particulates, with the liver recognized as a site for U accumulation in the body along with the skeleton and kidney [3]. Previously reported research of characterization of U concentration in sheep, Ovis aries, grazing near AUMs, a decommissioned U milling site, and downstream of a major U tailings pond spill that occurred in 1979 suggest low accumulation in tissues and organs [4,5]. However, little is known about the accumulation of U in sheep liver tissue based on their exposure to different types of AUMs (e.g., open pit, underground). The purpose of this study is to characterize the concentrations in the liver of sheep grazing on or near AUMs on the Navajo Nation. Statistical analysis comparing liver U concentrations between mining and non-mining areas was performed using Kruskal-Wallis and Dunn’s Test. Results suggest U concentration differences were found between the mining and the reference sites. Statistical analyses confirmed that the mining sites concentrations were similar regardless of the type of mining. The findings of this research confirm that U is present at measurable levels in the liver of the sheep