Lake Andes National Wildlife Refuge

 Located in South Dakota, these lands and waters are vitally important to the nation’s migratory bird populations – aquatic birds and songbirds nest here in great numbers. Lake Andes is a natural, shallow prairie lake whose water supply depends entirely on natural runoff. Lake levels periodically rise and fall, with the entire lake going dry about once every twenty years.Two dikes separate Lake Andes into three separate units, but the lack of a permanent water supply allows very little manipulation of water levels to encourage growth of aquatic foods or assure duck broods of adequate water in drier years. Only the Owen's Bay marsh, fed primarily by the waters from a free-flowing well, permits effective manipulation of water levels to maximize the bay's benefit to wildlife.