Ark Island lies at the mouth of the Aniakchak River on the north shore of Aniakchak Bay along the southeastern Alaska Peninsula, about 205 miles (330 km) southwest of Kodiak and 47 miles (75 km) northeast of Chignik, Alaska. The island’s unofficial name may derive from the splintered remains of a scow once used to maintain fish traps. The river drains Surprise Lake in the caldera of Mount Aniakchak, flowing southeast for about 36 miles (58 km) through Aniakchak National Monument and Preserve to the bay. Walter R. Smith and Arthur A. Baker of the US Geological Survey first recorded its name, describing it as the largest stream on the peninsula flowing toward the Gulf of Alaska. Three bays along the Gulf coast border the preserve. The two larger bays; Amber Bay to the north and Ani’akchak Bay in the middle, while the smaller Ku’jewlik Bay is to the south. All feature cinder-covered beaches between the sea and expansive freshwater lagoons. Ark Island may be the remnant of an ancient volcano built of Meshik Volcanics—from the early Oligocene to the late Eocene—comprising basaltic rubble and lava flows. Until about 3,650 years ago, Mount Aniakchak towered as an Aleutian Range stratovolcano, exceeding 7,000 feet (2,134 m) and composed of basalt and dacite. A massive eruption then removed roughly 3,000 feet (914 m) from its summit. The subsequent collapse formed a flat, ash-filled caldera that gradually filled with water until rising pressure breached a weak spot in the wall, triggering a flood that carved a cleft now known as The Gates. The most recent volcanic activity occurred in 1931, when an explosion scattered thousands of tons of ash up to 40 miles (64 km) away. Geologist and Jesuit priest Father Bernard Hubbard documented the event; his films, photographs and descriptions now serve as a benchmark for assessing the caldera’s ecological recovery.

The Aniakchak River provides one of the best salmon spawning habitats on the Alaska Peninsula’s Pacific coast. The west shore of Aniakchak Bay—located just south of the river’s mouth—offers a favorable site for habitation. Abundant fishing, shelter, and freshwater have attracted people for thousands of years, making this one of the few known prehistoric sites on the central peninsula. Archaeological evidence indicates that the central Alaska Peninsula was occupied, abandoned and re‑colonized repeatedly, perhaps in response to recurrent catastrophic volcanism. Although little is known about those who lived here before the cataclysmic eruption of the Aniakchak stratovolcano, it is unlikely the region was ever uninhabited. The eruption altered the landscape and likely buried any pre‑eruption traces of human activity. Lands closest to the caldera remained largely uninhabited for millennia, and the Pacific coast was not resettled until between 1575 and 1655 AD. The volcanic wasteland also marked the boundary between Aleut Unangan speakers in the southwest and Alutiiq Sugpiat speakers in the northeast. The narrow peninsula—only 45 miles (72 km) wide at Aniakchak—bridged the distinct environments of the Bering Sea and the Pacific, which likely spurred both trade and internecine conflicts among Native groups. In 1783, Russian explorer Gregory Shelikhov subjugated the Alutiiq on Kodiak Island and established the first nonnative settlement at Three Saints Bay. His fur trade empire soon dominated life on the peninsula, with traders conscripting locals to hunt or trap puffins, sea otters, seals and foxes for the Shelikhov-Golikov Company and later the Russian-American Company. Commercial fishing began at the river’s mouth in 1917 when the Columbia River Packers Association installed fish traps. Recognizing the bay’s excellent trap sites, the company operated for nearly 30 years, building a bunkhouse in 1924 and establishing a cannery in 1932 after razor clams were discovered—a move that quickly depleted the clam population. These events have left an indelible mark on the region’s cultural and economic landscape.

In 1978, President Jimmy Carter established Aniakchak National Monument under the Antiquities Act. The original monument covered 380,000 acres (150,000 ha) but excluded the area between the caldera and the coast. Two years later, the Alaska National Interest Lands Conservation Act redefined the unit as a national monument encircled by a larger national preserve extending to the peninsula’s south coast. The monument permits subsistence hunting by local residents; in the preserve, both subsistence and sport hunting are allowed. The Aniakchak Bay Historic Landscape District encircles the Aniakchak River from Aniakchak Crater to Aniakchak Bay. Designated a National Wild and Scenic River in 1980 by Congress, the river is navigable by small to medium rafts and kayaks. It flows about 1 mile (1.6 km) from Surprise Lake in the caldera to The Gates—a narrow gorge in the caldera wall—before plunging through 15 miles (24 km) of rocky rapids rated Class II to IV on the International Scale of River Difficulty. Downstream the river is Class I; after 5 miles (8 km) it slows and meanders toward the bay. In addition to the challenging rapids and cold water, the area endures notoriously bad weather, with winds up to 100 mph (160 kph) that can damage equipment and prevent aircraft from landing at the lake or bay. Brown bears are frequently seen along the river and near the bay, scavenging for food. These factors, combined with the region’s remoteness, have resulted in few visitations, making Aniakchak the least visited unit in the National Park system. Read more here and here. Explore more of Ark Island and Aniakchak here: