Historical land tenure policies often prevent tribal members from accessing and managing resources on lands to which they hold allotment titles. Tribal trust landowners continue to experience challenges in applying long-contested water resource rights for beneficial use on their land. This study examines the relationship between land tenure and water resource management in tribal lands. Conflicts arising from diverse land ownership types and the implications of water rights management of tribal trust and non-tribal assets are analyzed. Watershed analyses of landownership types are performed to provide a comprehensive picture of the extent of tribal control and management of water resources. These analyses provide an estimate of land within the reservation boundary not controlled by the tribe, thus highlighting the restrictions that such land presents for tribal resource management. To further detail the potential impact of these restrictions, the land tenure of the tribal land base is outlined, including the percentage of tribal trust, fee, or non-trust land types, with the goal of specifically addressing the potential limitations on water resource usage for allottee landowners on Crow tribal lands. Using highly fractionated lands as a proxy for idle lands, 33% of tribal trust lands were estimated to be precluded from water resource management. The convergence of large-fee land and fractionated idle land is identified as alienated land. The primary waterway basins consist of over 60% fee and idle land as alienated land. Fee and non-trust lands are subject to state control over water rights, and the reserved rights associated with idle allotted land are inaccessible to the tribal management authority. This leaves allottee landowners unable to use and manage their land and related water resources. The key to effectively managing tribal water resources is to ensure that all landowners have the means to participate in resource management.