Gooma wrote:
If the dog is well behaved and kept on a short leash, OK. How does he behave in a crowded situation? I think you, the dog and other visitors would be better off without the dog being a tourist. Some kids, and adults too, are afraid of dogs and some people are allergic. Do everyone a favor and leave the dog in the RV or at least in the vehicle while at busy areas in the park.
Dogs are absolutely not allowed on trails or boardwalks within Yellowstone regardless of how well behaved or how short the leash is. They need to stay in the car or the RV while touring the park. At elevation the solar radiation can be very high and even if the air temperatures are comfortable the interior of a car can heat up to dangerous levels. The good news is, for most people Yellowstone is viewed from the car and very short walking paths and boardwalks. If the dog is comfortable sitting alone quietly in the car for short periods of time (30 minutes or less) you will be able to see what 99% if park visitors see.