You can find historic land-use resources at:
The Owen Science and Engineering Library
The Owen Science and Engineering Library houses many historic maps and publications. The map library is located on the third floor.
You can find maps by using the WSU Search It library catalog and limiting your results to display just maps. Here is an image that demonstrates how to do that.
The Owen Science and Engineering Library also houses many historic science and engineering documents including many of the Washington State College Extension publications.
Holland and Terrell Libraries
The Holland and Terrell Libraries also contains many historic documents and Extension publications. It also has copies of many regional newspapers.
Manuscripts, Archives & Special Collections (MASC)
MASC, which is located on the bottom floor of the Holland and Terrell Library, houses countless historic agricultural documents ranging from early publications, ephemera, historical images, researcher notes and correspondences, local histories, and much more.