Lake Pend Oreille ( ) in the northern Idaho Panhandle is the largest lake in the U.S. state of Idaho and the 38th-largest lake by area in the United States, with a surface area of . It is long, and deep in some regions, making it the fifth-deepest in the nation and having a volume of 43,939,940 acre feet = 54 km3. The lake is fed by the Clark Fork River and the Pack River, and drains into the Pend Oreille River, as well as subsurfacely into the Spokane Valley–Rathdrum Prairie Aquifer. It is surrounded by national forests and a few small towns, with the largest population on the lake at Sandpoint. The majority of the shoreline is non-populated and all but the southern tip of the lake is in Bonner County. The southern tip is in Kootenai County and is home to Farragut State Park, formerly the Farragut Naval Training Station during World War II, of which a small part is still active and conducts U.S. Navy acoustic underwater submarine research. The surrounding forests consist of ponderosa pine, Douglas fir, red cedar, poplar, quaking aspen, hemlock, paper birch and western larch. Local animal species include white-tailed deer, elk, gray wolves, moose, mice, squirrels, chipmunks, black bears, grizzly bear, coyotes, mountain goat, cougar and bobcats, along with bald eagles, wild turkeys, osprey, owls, hummingbirds, hawks, woodpeckers, ducks, and the mountain bluebird. The lake is a home for several species of migratory water fowl. History Lake Pend Oreille was glacially formed during the ice age. It is also believed that the eastern side of the lake was in the path of the ancient Missoula Flood. The lake sits at the south end of the Purcell Trench, carved by glaciers moving south from Canada. The eastern side of the glacier is believed to have formed the dam for the Missoula flood, at the point where the Clark Fork river enters the lake between the Cabinet and Bitterroot mountains. The lake is made slightly larger by the dam at Albeni Falls, just east of Oldtown; the dam is high and operated by the U.S. Army Corps of Engineers. Along with Crater Lake, Lake Tahoe, Lake Chelan, and Lake Superior, Lake Pend Oreille is among the five deepest lakes in the United States. The area around the lake is the traditional home of the Kalispel Indian peoples. David Thompson established a North West Company