Marcus and Narcissa Whitman and the Opening of Old Oregon, by Clifford M. Drury.
Oregon Geographic Names, by Lewis A. McArthur and Lewis Ankeny
Washington State Place Names, by James W. Phillips
Shallow Grave at Waiilatpu, by Erwin N. Thompson
The Letters of Narcissa Whitman and My Journal, by Narcissa Prentiss Whitman.
The Great Command: The Story of Marcus and Narcissa Whitman and the Oregon
Country Pioneers, by Nard Jones.
Converting the West: a Biography of Narcissa Whitman, by Julie Roy Jefferey
Juggernaut: The Whitman Massacre Trial, by Ronald B. Lansing
Whitman Massacre of 1847, Sager
The Cayuse Indians, by Robert H. Ruby and John A. Brown
Prairie Traveler, A Hand-book for Overland Expeditions, published in 1859, by
Randolph B. Marcy
Stout-Hearted Seven, by Neta Frazier
Cobblestone Magazine — issues on Oregon Trail, Chief Joseph, Mountain Men
Daily Life in a Covered Wagon by Paul Erikson
A variety of books by Bobbie Kalman
If You Traveled West in a Covered Wagon, by Ellen Levine
Westward on the Oregon Trail, by Marian T. Place
Discover the Oregon Trail, by Bobbie Salts
The Story of the Oregon Trail, by R. Conrad Stein.
… and many more