Stock photography, photos: Old Turbine House & Millrace Stock photos of Old millrace and turbin house on the Big Sioux River. Photograph: © Jim Parkin Click for a larger image and more information Keywords associated with this stock photo: usa, us, untied states, america, sd, south dakota, sioux falls, sioux quartzsite, river, big sioux river, energy, hydroelectric, hydro, power, power generation, turbine house, millrace