The two lost backpackers rescued Wednesday in Denali National Park were far from where they thought they were and didn’t know they were the subjects of a massive search lasting four days and costing an estimated $120,000. But as they say, all’s well that ends well.

Situated a few miles south of Miami, Biscayne National Park is the only place in the world where a living coral reef lies adjacent to a large metro area. Biscayne’s metro periphery location, fragile resources, and heavy visitation make it one of our most vulnerable parks.

Backpackers Abby Flantz and Erica Nelson were rescued in good condition after being lost for six days in the Denali National Park wilderness. The two women, who had used a cell phone to help searchers locate them, were reunited with family members Wednesday afternoon.

Many nonnative plant and animal species that have invaded our national parks pose a danger to the native species. On Hawaii’s Big Island, invasive plants are threatening to wreak ecosystem havoc in Hawaii Volcanoes National Park. To combat this onslaught, the Park Service uses manual and mechanical removal, herbicide spraying, and biological controls.