Too much fun exploring! Some great spots for camping (boondocking). Rewards you with some great viewpoints of Darrington to Arlington, and the Skagit Valley on the other side. Barely a pothole, and easy to travel 20-30 mph! Just a fun drive.
38 miles in about 3 hours, and that was goofing around a lot. Didn't get to explore the side roads, but saw some great places to stop!