Washington State University is the copyright holder of Extension publications.
Basic policy on copyright is available on the WSU copyright page: publishing.wsu.edu/copyright/.
Authors must cite sources for any material within their publication that is not original work done by them. Authors must seek and receive formal permission to use any substantial portion of material (text, photo, illustration, table, etc.) not originally created by themselves, if that material is under copyright protection.
WSU Extension has a copyright permission request form available here: news.cahnrs.wsu.edu/getting-published/required-forms/.
Material available under a Creative Commons license may be used, depending on the terms of the license. The originator and the CCL must be cited per the requirements of the license.