Iliamna Lake, inland body of water, southwestern Alaska, U.S. It lies west of Cook Inlet (Gulf of Alaska), near Lake Clark National Park and Preserve (north) and Katmai National Park and Preserve (south). Named by Tanaina Indians, the lake was said to be inhabited by a mythical giant blackfish that would bite holes in canoes. The second largest freshwater lake entirely within the United States (after Lake Michigan), it is 80 miles (130 km) long and 25 miles (40 km) wide and covers an area of 1,150 square miles (3,000 square km). It drains southwest through the Kvichak River into Bristol Bay and the Bering Sea. The lake has several islands, including Porcupine, Flat, Triangle, and Seal islands, and it is noted for its game fish, especially rainbow trout. The active Iliamna Volcano (10,016 feet [3,053 metres]) lies northeast of the lake at the head of Tuxedni Glacier. The shores of the lake are dotted with small communities, inhabited predominantly by Alaskan natives; tourism is economically important for the town of Iliamna, on the lake’s north side.