Pilot Grove State Preserve is a historic protected area in rural Iowa County, southwest of Williamsburg, where a wooded knoll rises between the North English River and Old Man's Creek. With hickory, oak, and walnut trees and patches of virgin prairie, it preserves a landscape once distinctive on the open prairie. In the early years of Iowa settlement, when no other timber stood nearby, the grove served as an important landmark for pioneers traveling west and for people moving to and from Marengo. A cemetery was established beside the knoll in 1867, and the site was later restored to reflect its mid-19th-century appearance.