States plea to keep parks pristine columbian.com - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from columbian.com Daily Mail and Mail on Sunday newspapers.
Most states welcome visitors, who are vital to their economies. But the economic benefits are accompanied by crowds that can degrade the natural resources of fragile ecosystems.
Most states welcome visitors, who are vital to their economies. But the economic benefits are accompanied by crowds that can degrade the natural resources of fragile ecosystems.