Ed, if you don't have it you should download my key to lichen genera for the Pacific NW, which does include crusts. I recently posted a revision (Jan 2016). See the Literature section under Resources in the NWL website.
http://northwest-lichenologists.wildapricot.org/Literature
There is no comparable photographic treatment, though you would probably find Brodo et al. Lichens of North America helpful for that.