This sub-series includes letters to Abby Williams Hill from Native American people belonging to the Flathead, Sioux, and Nez Perce tribes. Hill met and befriended many Native Americans, particularly from the Confederated Salish and Kootenai Tribes of the Flathead Reservation in Montana, where she and her children had a lengthy stay in both 1905 and 1906. A detailed account of her stay on the reservation can be found in the Northern Pacific Railway Commission (1905-1906) journal in the Journals series.