July 6th, 2016 brings us 50-days away from the National Park Service Centennial. In this edition of the #CentennialCountdown we go back 50-years to 1966 when Bighorn Canyon National Recreation Area, Cape Cod National Seashore, Cape lookout National Seashore, Fort Union Trading Post National Historic Site, George Rogers Clark National Historic Park, Indiana Dunes National Lakeshore, San Juan Island National Historic Park, Wolf Trap Farm Park