The Flint Hills are a group of hills in eastern Kansas, extending from Marshall County in the north, to Cowley County in the south. The hills were created approximately 250 million years ago during the Permian Period. During this time much of the midwest, including Kansas, was covered with shallow seas. As a result, much of the Flint Hills are composed of limestone and chert. State nickname: The Sunflower State Other U.S. States Capital Topeka Largest city Wichita Governor Kathleen Sebelius Official languages None Area 82,277 mi²; 213,096 km² (15th)  - Land 81,815 mi²; 211,900 km²  - Water 462 mi²; 1,196 km² (0. ... Marshall County is the name of several counties in the United States: Marshall County, Alabama Marshall County, Illinois Marshall County, Indiana Marshall County, Iowa Marshall County, Kansas Marshall County, Kentucky Marshall County, Minnesota Marshall County, Mississippi Marshall County, Oklahoma Marshall County, South Dakota Marshall County, Tennessee Marshall County, West Virginia... Cowley County (standard abbreviation: CL) is a county located in the state of Kansas. ... The Permian is a geologic period that extends from about 280 to 248 million years before the present (mya). ... Limey shale overlaid by limestone. ... Chert Chert is a fine-grained silica-rich cryptocrystalline sedimentary rock that may contain small fossils. ...