In this photo released Monday, April 23, 2007 by the Illinois State Geological Survey shows a fossil, part of a fossilized rain forest discovered in coal mines in Vermilion County in east central Illinois. Geologists say the area dates to the Pennsylvania Age, 300 million years ago. Researchers are probing the fossilized area which covers about 15 square miles, all more than 200 feet below ground, and is probably the largest intact rain forest from that period ever studied. (AP Photo/Illinois State Geological Survey)