The Weaubleau structure is a probable meteorite impact site in western Missouri near the towns of Gerster, Iconium, Osceola, and Vista. It is believed to have been caused by a 1,200 feet (370 m) meteoroid between 335 and 340 million years ago during the middle Mississippian Period (Latest Osagean to Earliest Meramecian). It is listed by the Impact Field Studies Group as a "probable" impact structure.[2]