On November 26, 2018, Curator Peter Whiteley testified in Maricopa County Superior Court, Arizona, for the Hopi Tribe in a case to determine water rights in the Little Colorado River watershed. Based on field interviews with many Hopi elders and archival research, beginning in 1992, Whiteley presented two expert reports on:
a) the significance of water in Hopi traditional culture and society throughout Hopitutskwa, the area of aboriginal Hopi lands;
b) the history of Hopi water usages throughout Hopitutskwa since 1540 (court testimony focused on the period since 1846, when the United States proclaimed sovereignty over the area).