Traffic traveling to and from Mount Rushmore on the highways is typically not congested. Traffic will be heaviest in the middle of the day.
Once you are at Mount Rushmore the biggest traffic back-ups occur at the parking garage. The large volume of vehicles passing through the gates causes some congestion. Paying for parking is a quick process. Please be patient.
June, July and August are the busiest months. July 3rd, the day of the Independence Day fireworks display, the parking garage will fill up between mid-morning and early afternoon.