The archives also includes the State Library Photograph Collection, which contains 5,274 images of various subjects related to Washington's history, people, geography, and economic development, from 1851-1990. Here’s one of a Boeing 314 Clipper flying past Mt. Rainier.
You can either search the photo collection by keyword, or browse the collection titles. In searching for the photos of Asahel Curtis, I came across this one taken at Neah Bay, where a whale is being cut up by whale hunters:
Asahel Curtis began his photographic career in 1897 and chronicled much of the Pacific Northwest over the next several decades.
You can also find photos of historical figures, such as Ezra Meeker, who travelled the Oregon Trail by ox cart and was the founder of Puyallup WA.