Planning to rent a car from Rapid City airport in June/July 2014 and drop off at Jackson Hole (we're from the UK). Are the rental car returns on site at the airport; or off airport; or even in town? What time do they open? Our flight from JAC to Denver leaves at 0715am, so I'm not sure if we can drop off the rental car that early (e.g. 0530) - would we be better dropping it off the night before, and getting a taxi to the airport? Any insider information much appreciated - thanks.