Michelle Obama: Happy 98th Birthday to the National Park Service! All #NationalParks are offering #FreeAdmission today. What are you waiting for? #LetMove and celebrate by getting outdoors! (Photo via @USInterior)

Happy 98th Birthday to the National Park Service! All #NationalParks are offering #FreeAdmission today. What are you waiting for? #LetMove and celebrate by getting outdoors! (Photo via @USInterior)

via Instagram michelleobama