The Cahokia Mounds State Historic Site will welcome the equinox and the arrival of spring with a special dawn event March 20 at the “Woodhenge” solar calendar.

Visitors can gather at 6:45 a.m. Sunday, March 20, to see dawn break over the reconstruction of a calendar used when Cahokia Mounds was home to thousands of Native Americans. The huge circle of posts stands 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. No rituals or ceremonies will be performed out of respect for American Indian beliefs and culture.

 One definition for the start of spring is the vernal equinox, when the day is equally divided between hours of light and darkness. It arrives on March 20 this year.

Cahokia Mounds State Historic Site is just eight miles from downtown St. Louis, in Collinsville, Ill., off Interstates 55/70 (Exit 6) and Interstate 255 (Exit 24), on Collinsville Road.

The Interpretive Center is open 9 a.m. - 5 .pm. Wednesday through Sunday. There is no admission fee but we do suggest donations of $7 for adults, $5 for seniors, $2 for students and $15 for families.

For more information call 618-346-5160 or go to www.cahokiamounds.org.

The site is operated by the Illinois Historic Preservation Agency. IHPA protects the state’s historic resources, which contribute to education, culture and the economy. IHPA sites include ancient burial mounds, forts and buildings erected by settlers, and homes connected to famous Illinoisans.