Old Mission State Park in northern Idaho preserves the Mission of the Sacred Heart, or Cataldo Mission, centered on a church built from 1850 to 1853 that is the oldest standing building in Idaho. The mission grew from efforts beginning in 1831 to establish a Catholic presence in the region, was first founded along the St. Joe River, and moved in 1846 because of flooding. Designed by Jesuit missionary Antonio Ravalli and built by Indigenous workers without nails, the church is noted for inventive frontier materials and decoration. The site later served travelers on the Mullan Road and includes a rebuilt parish house, cemeteries, and other park features.