Dec. 14, 2005, wasn’t one of Missouri’s best days. A catastrophic breach in the 4,365-acre-ft upper reservoir atop Proffit Mountain, the state’s highest peak, knocked the 440-MW Taum Sauk Pumped Storage project off-line, devastated a popular state park and earned St. Louis utility Ameren UE a $10-million federal fine, the largest ever for a hydroelectric facility.