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Photos property of Matthew Browning

Browning had given this little talk many times. But on this day, in August 2009, he saw another ranger deliver it to a boy at the park restaurant, about age 8, with a fist full of rocks—rocks, Browning noticed, from the gravel road. “It was gravel we bought at the local store,” Browning says. “It made me sick. The boy was crestfallen. He was so excited about coming to the park that he wanted to take a little memento back with him. More than feeling empowered or excited to protect the natural world, now he is going to associate going to state parks with getting into trouble.”