Speaking of Washington highway history, WSDOT has a new ferry, the Sanpoil, on WA21. This crosses Lake Roosevelt north of Wilbur.
WSDOT acquired this run in 1930, and ran the Martha S from 1948 to this year.
The new boat was constructed near Portland, and trucked in 3 large pieces to a final assembly point near the GC Dam.
http://www.flickr.com/photos/wsdot/sets/72157632986894243/http://www.flickr.com/photos/wsdot/sets/72157635285953917/WA21 to the Keller campground and ferry drops 800' with a couple of serious 180deg curves. But plenty of RVs use the campground (and marina).