While traveling Interstate 70 in Utah last Summer we encountered very high winds pulling our 31' fifth wheel. When I was checking out of the campground in Grand Junction Colorado the lady told us to beware of the wind. I had no idea what she was talking about. The sky was blue, the wind was not blowing and we had anticipated a good travel day. After driving about 50 miles into Utah the wind all of a sudden picked up. The velocity was really strong and it was coming out of the South hitting our 5th wheel broadside. This 80 mile stretch of interstate is VERY desolate with NO services, stores or anything. It looks like being on the moon. The wind was howling, dust was so thick I could see only a short distance and I had both hands on the wheel with sweaty palms. The entrance steps on the opposite side from where the wind was blowing kept unfolding. I would stop and put them back up only to have them blown out again. I finally stopped the 4th time and tied them in the closed position. I could only drive 35 to 45 mph and was very uncomfortable with the situation!!! It seemed like hours before the wind settled down. I've never seen anything like this.
Our 5th wheel, other than having the steps unfold, never wavered and performed very well. We made it safely without any incident.
I can tell you 5th wheel trailers do well in high winds! However you should slow down. Later that evening while watching the evening news from our camp in Panguitch we heard about two 18 wheelers near Salt Lake City that were blown over in the high winds!!!!!