COLLINSVILLE, Ill. (AP) — The Cahokia Mounds State Historic Site will welcome spring with a special dawn event at the “Woodhenge” solar calendar. The March 22 ceremony will be followed later in the day with a presentation on the Native American tradition of sky watching. Visitors may gather at 6:45 am. to see dawn break over the reconstructed calendar used when Cahokia Mounds was home to thousands of Native Americans. Posts that stand in a large circle comprise the structure. It is about one mile west of the site’s interpretive center on Collinsville Road. An archaeologist will explain the discovery, form and function of Woodhenge while awaiting the sunrise. The event features no rituals or ceremonies out of respect for American Indian culture.