I just got back from the Burr Trail driving from Boulder to Bullfrog. From Boulder to the bottom of the switchbacks it is a beautiful drive with somewhat of a pucker factor on the switchbacks and moderate washboards. From the bottom of the switchbacks to Bullfrog the road had the worst washboard conditions I have ever seen. I tried airing down, driving fast, driving slow....nothing worked. To prevent vehicle/camper destruction I drove between 5 and 10 mph. Myself, I would never drive the lower section again.