I just read _ The Land is Bright _ by Archie Binn. Written in the 40's about a wagon train on the Oregon Trail. He was a Seattle writer. I think OSU recently reprinted most of his work.
Don Berry was an Oregon author with a trilogy of loosely connected historical fiction set in NW Oregon's 1850s.
The Worst Hard Time: The Untold Story of Those Who Survived the Great American Dust Bowl _ by Timothy Egan is a well written study of the the causes and effects of the Dust Bowl. This book really gets you into the lives of a small town in the heart of the dust bowl. One reason he wrote the book was he realized that the last survivors of the period were dying and there was little record beyond archived material.
Weirdly, Carol is reading the diary of Alexander Ross and I'm reading the biography of Robert Stuart; fur trade and explorer contemporaries in the 1810s in Astoria Fort Vancouver area.
I used to spend hours in Smith Bros. used books (lived in Florence for a year or so), Now it is Powells, or online at Abebooks and Alibris.