I've been working the South Platte. Added river banks from Chatfield Dam (south of Denver) to east of Greeley. Someday, I'll get to Nebraska, and maybe meet whoever is adding the banks upstream from the Missouri. Also, there's a newly-opened stretch of the South Platte River trail along the east bank of the river through Littleton. Biked and GPXed this stretch; it's not yet in Bing imagery but is now in OSM!