At the entrance to the local fairgrounds, they have a typical rock. I think that the fence is there to protect the rock, or protect the cars that might run into it.

This native stone is used in many buildings in the Sioux Falls, South Dakota area. Not so many years ago, it was quarried and used regionally.

The Picture-in-a-Picture shows a LOT more of these rocks at the Sioux Falls park.

You see these boulders around, as the farmers who ploughed them up, decided they were too large to completely remove, so they shoved them over to the corner of their field.

The plaque indicates the entrance to the fairgrounds.

You can see the parking tram in the background, taking fair visitors to and from the parking area.

Image processed with GIMP.