The sky is broad, the land is rugged and the air fills your lungs with joy. But for many adventurers, the true appeal of a trek through a national park is the fine detail: the living flora and fauna, often rare and unusual, that quietly populate the landscape. U.S. national parks are each home to an average of 415 species of wildlife. Each species plays an essential role in the park's ecosystem, and each park has its own unique characters, sights and sounds. From tiny but tough pikas to trumpeter swans and Dutchman’s breeches, these wild expanses are full of surprises. So, if you were going down to the park today, which parks would you be most likely to run into a surprise? Casago analyzed National Park Service data to find out which parks have the most wildlife and plants per 100 km² and which have the greatest biodiversity overall. Key Findings Congaree in South Carolina has the greatest density of wildlife species, with 362 per 100 km². However, Biscayne in Florida has more o...