Garter Snakes, an endangered species, find refuge at San Francisco International Airport
There are over 1,300 endangered or threatened species in the United States today. Although some are teetering on the edge of extinction, many safely live on millions of acres held in trust by the federal government. Not all of that land is as remote as you may think. In fact, if you're an air traveler you may have driven – or flown – right by it.