Cayuse

Cayuse refers to a Native American people of the Pacific Northwest. Historically, they inhabited the Columbia Basin and surrounding areas in what is now eastern Oregon and southeastern Washington, particularly along the Walla Walla and Umatilla rivers. The Cayuse spoke a language of the Sahaptin branch, closely related to other Plateau languages. In modern times, most Cayuse people are enrolled in the Confederated Tribes of the Umatilla Indian Reservation (CTUIR), which also includes the Umatilla and Walla Walla peoples.

Prior to extensive European-American settlement, the Cayuse practiced fishing, hunting, and seasonal transhumance, with horse culture playing a significant role after contact. The Whitman massacre in 1847 precipitated the Cayuse War against American forces; subsequent treaties in 1855 ceded lands and created reservations. Population declined due to disease and displacement, and the Cayuse became one of several tribes within the CTUIR. In contemporary tribal governance, Cayuse identity persists within CTUIR, and language and cultural revitalization efforts continue.

The Cayuse language is considered endangered, with revitalization programs documented by CTUIR and linguists; it remains a focus of cultural preservation alongside related Sahaptin languages.

The name "Cayuse" is also used by an Oregon-based software company, Cayuse, Inc., which develops research administration software for higher education. Its suites support grant submission, award management, and regulatory compliance workflows for institutions, including IRB and IACUC processes. The Cayuse platform is used by universities to manage proposals, awards, and compliance documentation.