The World Wildlife Fund has designated the Flint Hills as an ecoregion, distinct from other grasslands of the Great Plains. Explorer Zebulon Pike first coined the name the Flint Hills in 1806 when he entered into his journal, “passed very ruff flint hills”.
Regions of Kansas and Oklahoma, showing the Flint HillsThe Flint Hills were created approximately 250 million years ago during the Permian Period. During this time much of the Midwest, including Kansas and Oklahoma, were covered with shallow seas. As a result, much of the Flint Hills are composed of limestone and shale with plentiful fossils of prehistoric sea creatures. The most notable layer of chert-bearing limestone is the Florence Limestone Member. It is approximately 45 feet thick; numerous roadcuts of the Florence Member are prominent along Interstate 70 in Riley County, Kansas. Many of the honey-colored limestones have been used for building blocks. The non-chert-bearing limetones are best for this, since the chert is extremely hard to cut, yet it can fracture quite easily.
Beginning in the mid-1800s homesteaders replaced the American Indian in the Flint Hills. Due to shallow outcroppings of limestone and chert, farming was not practical over much of the area, and cattle ranching became the main agricultural activity in the region. Still sparsely developed, the Flint Hills represent the last expanse of tallgrass prairie in the nation. There are four tallgrass prairie preserves in the Flint Hills, the largest of which, the Tallgrass Prairie Preserve, near Pawhuska, Oklahoma, also boasts the largest population of bison in Oklahoma. The other preserves, all located in Kansas, are the Tallgrass Prairie National Preserve, Flint Hills Tallgrass Prairie Preserve and the Konza Prairie Biological Research Station.
