Preride report: http://blog.seattlerando.org/?p=1135
Route on RWGPS: https://ridewithgps.com/routes/27364336
You'll start in Olympia and control in Centralia before heading out to Morton and Mossyrock via Centralia–Alpha Road. From the climbs of Lewis County, you'll head south along the Cowlitz River to Longview and across everyone's favorite bridge to Oregon (actually, it's terrible. Use caution and watch for logging debris in the shoulder). Climbing out of Rainier, Oregon, you'll reach Apiary, named in the late 1800s by a beekeeping postal worker, but better remembered by you as the false summit before Camp Wilkerson (kilometer 233). A well-earned descent to the Nehalem River will bring you to Vernonia, Oregon, your last chance to buy supplies before the overnight control in Astoria, 100 kilometers away. Water and bathrooms are available in the Jewell Meadows Wildlife Area (watch for elk) about halfway to Astoria and just before your climb over the Northern Oregon Coast Range. Overnight in Astoria and get some rest before day two.
The second day of this 600 begins with the epic Astoria–Megler Bridge, which is the longest continuous truss bridge in North America. You'll start high on the Oregon cantilever-span side; keep that momentum for the low central span and you'll be across before you know it. The route then follows the Lewis and Clark Highway past Dismal Nitch Cove (Captain William Clark was having a rough time of it) and up through Naselle. Continuing north along Willapa Bay, you'll pass through Nemah, Bruceport, and South Bend before arriving in Raymond, home to the word's most interesting 24-hour Chevron (and your first opportunity for supplies since Astoria). Oh, and other places to get food, too. You'll then follow the coast up and around to Cosmopolis where I hear they have another Chevron. At this point, with less than 100 kilometers to go, you'll probably be feeling like Captain Clark, but the lovely Blue Sough Road should give you a little pick-me-up before Montesano. According to Wikipedia, settlers nearly named it Mount Zion, but "Samuel James suggested 'Montesano' as having a more pleasant sound and meaning about the same." I don't know about that, but it's where the Melvins are from, so there you go. I digress. The route continues along Monte–Elma Road and into McCleary where you can get a nice bite to eat at the Rain Country Restaurant before the final climb into Olympia on Hwy 8. Zigzag across town to the finish at La Quinta: you're done!