Welcome to the forum Jeremy. All will just depend on what your RV is setup for. If you have 50 amp you will probably need adapers for 50 to 30, 20. If you have 30 amp, most likely, you will probably need no adapters but never hurts to have all adapters.
Jeremy the amperage is what allow power to your Camper. There are 50 amp for the larger motor homes and it drop down to a 30 amp and down to a 20 amp. If you are in Yellowstone in the summer it going to be hot, so if your camper has 2 air condition then maybe you would need a 50 amp service. I have a 36' MH with a 30 amp service, which means I can't have the hot water heater on electric and use the microwave at the same time. it would draw to many amps and tripped the breaker.The heaters are heated by propane and blown thru out the mh by 12 volts blowers, no problem. you can step down on your amps but you can't go up ie 30 to 50 amp but 50 to 30 is OK. Good luck on your trip. BTW there will be others who will correct me or add to what I have stated. We have some very smart people on this forum. :laugh: