West Branch, Iowa— Each Sunday in June and July a park ranger leads visitors through the 81-acre tallgrass prairie at Herbert Hoover National Historic Site. Join to learn how and why the National Park Service is reconstructing this endangered habitat as part of the landscape commemorating Herbert Hoover's life, and what is in store for the future. The walks begin at the tallgrass prairie observation deck by the gravesite parking lot at 9:30 a.m.