"4.3"^^ . "2012Z"^^ . "Jefferson County"@en . . "13.8997"^^ . "1855Z"^^ . . . "1.44262e+09"^^ . "Jefferson County (county code JF) is a county located in the U.S. state of Kansas. At the 2010 census, the county population was 19,126. Its county seat is Oskaloosa, and its most populous city is Valley Falls.Jefferson County is included in the Topeka, KS Metropolitan Statistical Area."@en . "6.21597e+07"^^ . "1.38046e+09"^^ . . . . "18945"^^ .