Thank you all for your advice. We had a great ride ... and if you like I've posted some pics' on my facebook site
http://www.facebook.com/#!/holway.jim
From Spokane (Oct 1) we rode to Davenport on Day 1 ( a very short day since it took about 4 hours to get my bike re-assembled before heading out). Beautiful back road N. of Rt2 between Reardan and Davenport. Day 2 was Davenport to Wilbur .. RT 2 was good through here. Caught a ride to Grand Coulee to make up for late start on Day 1. Awesome fresh fruit stand S. of Colville ... then hit a 35 - 45 mph headwind ... after riding about 2 miles in lowest gear for an hour a passing pickup gave us a ride to Nespelem .. then after waiting for Sonny to finish work at the Tribal Community Center he drove us via the back road (would be great ride without the headwind!) on to the town park in Okanogan where they allow camping in the park. At this point we followed RT 20, with occasional back roads, all the way to Marblemount (Adventure Cycling Assoc - Northern Tier, map covers this area along 20). A number of forest service campgrounds along this area, beware that by Oct 1 they have turned off the water in most of the campgrounds so you've got to carry whatever you might need... took the parallel road S of RT 20 past Rockport and then headed S to Darrington. 3 mi west of Darrington on 520 there is a County run campground. Normally $20/night but no one was around and perhaps was officially closed by this time of year. Sometime would love the take the long way around from Darrington (headed S then west) to Granite Falls. But .. .on our last day of riding we had to get all the way into Seattle so I could get the bike back in a box to fly back to Phoenix the next day. Anyway ... 520 into Arlington was a nice ride. Then there is rail to trails from Arlington to Snohomish .. nice trail. From Snohomish into Seattle there is a route planned out Generally - Broadway to Malby, then smaller roads parallel to 520 to Woodinville and then picking up the Burke-Gillman Trail the rest of the way into downtown Seattle. It was an awesome tour ... great moutain passes, awesome downhills, beautiful countryside, even perfect weather (though 20 degrees in the morning before climbing Washington Pass was a bit cool). Mostly a priceless opportunity to ride with my son.
Thanks again for all the great route suggestions.
Jim