We've been thinking the same thing. Looking into it now. A friend and his SO are really jonesing to do the route. I ran across a link/a guy's journal that turned it into a "500K" by riding from Spokane(dedicated trail on the way out and through the "northern Palouse"/rolling wheat fields on the way back) . From what I'm reading, the cooler/wet season starts +/- the third week of September. We are tentatively thinking last week of August and spill into Sept as needed. Haven't locked it in yet.