It's because WA and OR have lost a lot of forest trees to disease and insects. They are trying to prevent wood from other areas from introducing new diseases or insects. There have been studies where NW Pacific organizations bought untreated firewood from other states and kept it to study how many were carryers of new diseases and insects. It has become quite a problem.
Edited by Carol Christensen, 19 June 2020 - 10:02 PM.