known historically as Bluestern Pastures or Blue Stem Hills, are a group of hills located in eastern Kansas reaching into north central Oklahoma, extending from Marshall County and Washington County in Kansas in the north to Cowley County, Kansas and Osage and Kay counties in Oklahoma towards the south. The people of Oklahoma usually refer to the same geologic formation as the Osage Hills or The Osage.
The Flint Hills are designated as a unique ecoregion due to it having the most dense coverage of intact tall grass prairie in North America. Because of its rocky soil, the early settlers of European origin weren’t able to plow the area, causing the predominance of cattle ranches, which then were largely benefited by the tall grass prairie. The Flint Hills Discovery Center opened in Manhattan, Kansas in April of 2012. The center is a history and science museum that focuses on the Hills.
The highest point in the Flint Hills is Butler County High Point, with the elevation measured at 1,680 feet. These Flint Hills were formed about 250 million years ago during the Permian Period. During this time, the majority of the Midwest, including Kansas and Oklahoma, were blanketed with shallow seas. That resulted in much of the Flint Hills being made up of limestone and shale with abundant fossils of prehistoric sea creatures.
The most prominent layer of chert-bearing limestone is the Florence Limestone Member. It’s about 45 feet thick; a number of road cuts of the Florence Member are famous along Interstate 70 in Riley County, Kansas. Many of the honey-colored limestones have been utilized for building blocks. The non-chert-bearing limestones are superlative for this, because the chert is very hard to cut, yet it can break quite easily.
Image Caption: A tallgrass prairie in the Flint Hills, northeastern Kansas. Credit: Edwin Olson/Wikipedia