Question: What is the name of a National Preserve located in the Flint Hills region of Kansas and is home to a population of genetically pure American bison?
Sentence (from "Tallgrass Prairie National Preserve"): Of the 400,000 square miles (1,000,000 km) of tallgrass prairie that once covered the North American continent, less than 4% remains, primarily in the Flint Hills.
Relevant evidence: No