Routing advice needed in Washington state.

A friend of mine hauled for dirt merchants for years. For the last 10 he’s been hauling for a couple of enviro/vac truck companies. His trailers all have the fancy NASA engineered tailgate seal, sample hatches, leachate drains and dry tarp systems and I don’t know what kind of #### on them. Those 4 are the most expensive end-dump trailers I’ve ever seen. I was more shocked by how much and how far that kind of special dirt gets trucked sometimes though. Weird little niche.