In the darkness, flames will be seen burning up prairie grass at Marr Park this Tuesday. The annual Night Prairie Burn will be held Tuesday at 8 p.m. The Washington County Conservation Board with the Ainsworth Fire Department will be burning the north prairie. The program will also include a discussion about the role of the prairie in Iowa’s history and how prairie fires impacted those that lived here in the past. The burn could take as little as 15 minutes.