I rode across the Sylvan Pass into Yellowstone, through heavy snow/sleet, in early June . Finding the camp grounds closed . Was blown off the Bear Tooth pass outa Red Lodge 3 times and snowed off the Togwotee Pass, escaping the Tetons . Snowed outa the Sunlight basin in late June trying to get back to Red Lodge . In between there was rain, lots of rain . All these memorable escapades happened in the month of June . You might want stay away from the Yellowstone/Teton area in June . That said, I'd do it again, believe it or not . I had just enough fowl weather gear for that caper . Ride safe and enjoy where you do go .