Glasford crater is a buried meteor impact site in southern Peoria County, Illinois, near Cowser and Kingston Mines roads, and one of only two known meteor craters in the state. Hidden beneath farmland, it is about 4 kilometers, or 2.5 miles, wide and likely formed in a marine setting during the Late Ordovician less than 430 million years ago. The crater was discovered through drilling for underground natural gas storage, identified as a probable impact structure in 1963, and later confirmed by shatter cones found in the 1980s. Researchers have linked it to the Great Ordovician Meteor Shower and possible climatic effects.