Squirrel Hollow Park, along the North Raccoon River southeast of Jefferson, Iowa, was established in 1934 and is the second oldest county park in the state. Covering 60 acres and adjoining a 147-acre wildlife management area, it remains shaped by riverfront improvements from the 1930s. In 1991, it was listed as a historic district on the National Register of Historic Places for ten contributing features designed by the Central Design Office at Iowa State College and built from 1934 to 1936 through New Deal programs. These include a shelter house, latrines, fireplaces, entrance portals, a retaining wall, a ball diamond, and the park’s gravel road system.