Aniakchak Volcano – Shaping the Cultural and Physical Landscape of the Alaska Peninsula

Present-day view inside Aniakchak Caldera featuring Surprise Lake. Prior to the draining of the Caldera, this lake once was five hundred feet above its currently level.

The landscape of Aniakchak is a vibrant reminder of Alaska's location in the volcanically active Ring of Fire. In spite of such violent volcanic events, the living world, animal and human, eventually adjusted, recovered, and endured. The history of Aniakchak Caldera exemplifies the destructive force of nature while also demonstrating the resiliency of people.

The Creation of Aniakchak Caldera

Aniakchak was a towering 7,000 foot tall volcano until its summit collapsed during a massive eruption roughly 3,500 years ago, creating the roughly 6-mile wide Caldera.

Long before this though, people had called the Alaska Peninsula and the adjacent Kodiak Island home, with the first evidence of humans dating back 9,000 years as hunters left behind traces of their chipped tools. Bristol Bay, Katmai, Kodiak, Port Moller, and the Shumagin Islands all became important cultural hubs on or near the Alaska Peninsula. While salmon was always an important resource, between 4,000 and 5,000 years ago, rivers stabilized in this warming-post glacial environment and began to spawn in large numbers. For many of the peninsula's inhabitants, salmon quickly became the axis of their economy and the hub of their culture. When the fish were spawning, it’s likely many families or bands gathered at the headwaters of Naknek, Becharof, Ugashik or Chignik lakes to set their nets.

Because the pyroclastic flows from the eruption of the Aniakchak would have annihilated anyone living within a 50-mile radius of the volcano and covered up any possible trace of their existence, we do not know if people lived in the immediate vicinity of the Caldera area. However, archaeological evidence from the nearby Ugashik lakes, just outside of that radius, suggests that around this time, humans disappeared from the record, killed or driven out by ash spewed from Aniakchak. Archaeological records show people would not return to the central peninsula area until at least 1,500 years after the eruption.

The Draining of the Caldera

In the years after the caldera-forming eruption, rainwater and seasonal runoff began to wash over, and eventually flood, the Aniakchak Caldera. Over the decades, the Caldera rim, acting as a circular dam, filled with water. This ancient lake was on average one hundred meters deep and covered about half of the Caldera floor.

Approximately 1,800 years ago, when the Caldera lake was at its deepest—approximately five hundred feet above the current lake level—earthquakes rattled the Caldera. Large waves rushed over the lowest point on the Caldera rim, causing weakened rock to burst at an area now known as The Gates.

The catastrophic draining of Aniakchak's Caldera lake through The Gates drastically reshaped the land surrounding the Aniakchak River valley and Aniakchak Bay. The flood carried so much sediment that deposits displaced nearly a quarter of Aniakchak Bay with a complex of beach berms and sand dunes. By the time of this event, humans had occupied Aniakchak Bay, as well as the adjacent Kujulik Bay. Though little information exists about these people who settled on the bluff overlooking Aniakchak Bay, archaeologist and geologists speculate that they met a catastrophic end as this massive flood annihilated most intertidal life and Aniakchak Bay was then unoccupied for several hundred years.

The Impact on the Cultural Landscape

At times, the region was abandoned, but people and animals alike always came back. About 1,600 years ago, people started living, albeit seasonally, in fairly permanent house sites along the Aniakchak Pacific coastline. House sizes became bigger and more numerous, and communities began to form, resembling the more organized village sites found in other Alutiiq regions like Katmai and Kodiak. Within four hundred years of their return, people occupied coastal sites throughout Aniakchak Bay, in Kujulik Bay, and on Kumlik Island.

Artifacts show that people fished the rivers and bays that fronted their villages. They dug and ate clams, hunted sea mammals, birds, and whales. The placement of these artifacts, shells, and bone material found in the numerous refuse heaps suggest that these ancient residents processed food, made stone and bone tools, and crafted other utility items, like oil lamps, inside the villages. Fish hooks, net, and line sinkers found at the sites tell us that fishermen caught salmon, herring and cod.

There is also evidence that the violent activity of Aniakchak positively shaped the cultural evolution on the Alaska Peninsula. Volcanic ash eventually fertilized post glacial coastal plains, attracting abundant game to the region. The people of the peninsula learned to use hot springs that formed near the volcano to cook fish, sea mammals, and edible roots. To the south, people used sulfur as a fire starter, collecting it at or near the vents of active volcanoes. Hunters and fishermen made fairly extensive use of volcanic rocks, including pumice floats for fishing or as an excellent abrasive to fashion other tools. Obsidian, volcanic glass, became a rare and highly prized stone material. Like the bears, birds, and fish, the people living along the Alaska Peninsula learned to adapt to their volcanic world and utilize the resources that it provided.

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This information is adapted and abbreviated from Beyond the Moon Crater Myth, A New History of the Aniakchak Landscape- A Historic Resource Study for Aniakchak National Monument and Preserve. Find the full publication here.