Black Hills Institute of Geological Research (Black Hills) (plaintiff) collected and restored fossils for display in museums. In August 1990, Black Hills was excavating fossils in South Dakota. A Black Hills researcher uncovered the fossil of Sue, a Tyrannosaurus rex, on a ranch that the United States held in trust for the sole use of Maurice Williams, an American Indian. Black Hills purported to purchase from Williams the right to excavate Sue. Black Hills then moved the bones to a location where scientists could restore the fossil. In May 1992, federal officers seized Sue and moved the fossil to the South Dakota School of Mines and Technology, on the ground that Black Hills’ removal of Sue violated federal criminal statutes relating to federal land. Black Hills brought suit against the United States (defendant) to quiet title to Sue, arguing that Sue was the personal property of Williams and was thus freely transferable. The district court held in favor of the United States, and Black Hills appealed.