The federal barriers were set along 20 miles of the parkway, starting at a government-built parking lot at President George Washington’s Mount Vernon home and continuing northwards to scenic overlooks in McLean, Va.

“I’ll take my chances,” said one man as he unloaded his two children on a grassy verge beside Roosevelt Island, just across from Washington’s Georgetown district.

But their day in the sun was darkened by a locked gate on the narrow bridge from the parkway to the island that celebrates President Teddy Roosevelt, who is widely regarded as the first presidential advocate for national parks.

Motorists who pushed through the barriers were applauded by other Americans.

“They’re right to do that,” a cyclist told The Daily Caller as motorists drove through an opened barrier at a private marina near the Belle Haven Country Club, located just south of Alexandria, Va.