John Davis trekked 6,000 miles to call for conservation of North America's wild lands.
John Davis just arrived in D.C. from Florida, and his legs are tired.
"I'm using muscle-powered means of transit," he says. "Hiking, bicycling, paddling, a little bit of swimming, sailing and maybe at the end cross-country skiing."
Davis began his journey in Florida in February. He plans to end in Canada. Along the way, he's studying wildlife and talking up conservation with local activists.
"We need to connect the isolated patches of wildlife habitat we have in America," he says.
Here in D.C., he's been impressed, he says, by the old trees in Rock Creek Park, and by the bike lanes -- which he plans to use as he makes his way out of the city today.