IDOT Planner Dakin Schultz said no human remains were found, but the highway design from Minnesota Avenue east to Correctionville had to be narrowed to minimize impacts to the site.

Schneider said the geoglyphs are similar but not the same as the Effigy Mounds burial mounds in eastern Iowa near the Mississippi River. He described geoglyphs west of Correctionville that are V-shaped trenches dug in the shape of animals, including one like a buffalo.

Schneider said some burial sites date back 500 to 600 years ago, while IDOT personnel found geoglyphs that were made about 1,200 years ago. Those have not been removed, but are kept in confidential spots, so as not to disturb the items of cultural significance.

The Woodbury County Conservation Board is processing a memorandum of understanding with the Iowa Natural Heritage Foundation to get assistance in acquiring roughly 90 acres of land, in a timbered area, to protect the cultural resources west of Correctionville.

"The Correctionville community is planning to develop an area to interpret the cultural resources and the Conservation Board would hope to collaborate with the community on this potential attraction," Schneider said.