A huge swath of the United States used to look a lot like the Kansas prairie.
More than 170 million acres were covered by tallgrass prairie, an ecosystem of 40 to 60 different types of grasses and wildlife.
Agriculture and urban development eventually swallowed up much of the prairie, and less than 4% remains, mostly in the Flint Hills of Kansas. Meander along nature trails at the Tallgrass Prairie National Preserve, which protects about 10,000 acres today.
The preserve, about 90 miles northeast of Wichita, is where the Nature Conservancy and the National Park Service re-introduced bison to the prairie in 2009. It was the first time bison have roamed the preserve’s land in over a century.