Pig's Eye Lake is an undeveloped 1159 acre natural area surrounded by river industry. It contains one of the largest heron and egret rookeries in a metropolitan area in the upper midwest. Recently eagles have established nests there and some of them winter there. The peninsula where the rookery is, is protected by the Department of Natural Resources as a Scientific and Natural Area. The area provides spectacular bird watching. The herons and egrets return to St. Paul around St. Patrick's Day, March l7. Best bird watching is on the south side of the Mississippi River from the bluffs in South St. Paul.