Took a buddy on a long, but fairly easy, gravel ride on the Whitehorse Trail. We parked at the trailhead lot located a mile west of the Oso General Store and rode the 19 miles to Darrington. The trail is in good shape with a couple closure warnings that really have no visible worries to justify them so we ignored them. There is some Stillaguamish River project work being done by the County but those signs were only for truck traffic warnings. We had lunch at Moe's in Darrington and then returned the 19 miles back to the trailhead. 
Going through the Oso slide memorial was very nice and a good effort was done to represent the scientific and human events that had occurred. The ride was long but enjoyable. The Trailforks ride log with some pictures can be found here.