The Marcus and Narcissa Whitman collection contains materials related to Dr. Marcus Whitman and his wife, Narcissa Prentiss Whitman, who arrived in the Walla Walla Valley in 1836 where they established the Waiilatpu Mission and lived until they were massacred in 1847.

The Whitman Mission National Historical Site Collection, which dates from 1947 to 1987, contains materials related to the Whitman Mission Historical Site, a memorial for Marcus and Narcissa Whitman and their impact on the Oregon Trail and the Native American population. The collection contains informational booklets, newspaper clippings, correspondence, and an academic paper entitled "Whitman Mission Overview.”