Broken Kettle Grasslands, owned and managed by The Nature Conservancy (TNC) in Iowa, recently held their annual bison roundup. Partners and volunteers from throughout the region helped round the bison up to check the health of the animals, weight them, and vaccinate them before releasing them back onto the prairie. Bison were, for thousands of years, an integral component of prairie ecosystems. TNC reintroduced bison to help control invasive species and improve prairie habitat. Broken Kettle, north of Sioux City along Loess Hills National Scenic Byway in Plymouth County, includes the largest remnant prairie and largest roadless area in Iowa. This area is the only known site with a population of prairie rattlesnakes in the state. The bison at Broken Kettle came from Wind Cave National Park and are called genetically pure since they have no cattle ancestry like most other bison found in the country today. The herd totals more than 200 and they spend the rest of the year roaming approximately 1,900 of the preserve’s 3,000 acres.