Pilot Grove State Preserve is a historic site located southwest of Williamsburg, Iowa, United States in rural Iowa County.

The site is a wooded knoll surrounded by prairie between the North English River and Old Man's Creek.

It consists of hickory, oak and walnut trees, along with patches of virgin prairie covered with bluestem, gramma, switch and Indian grasses, and a variety of native prairie wildflowers.

There was no other timber in the area during the early years of Iowa's settlement, and it was a landmark for the pioneers traveling west across the state.

[2] It was given its name because it gave people who traveled to and from Marengo, Iowa a sense of direction.