Valley Forge National Historical Park

This guide to Valley Forge National Historical Park in Philadelphia traces what happened to the ground beneath these old encampment fields once the deer took over. By 2009 the herd here had grown to nearly seven times what ecologists say a healthy forest can carry, with no predators and no hunting allowed to check them, so every seedling that sprouted got eaten before it had a chance. You'll hear how the park, built to honor Washington's ragged army, decided in 2010 to try something unusual for a place devoted to memory rather than management. Look down at the forest floor as you walk and judge for yourself what two decades of bare dirt looked like.