Mount Wrangell is a massive shield volcano

Shield volcano

A shield volcano is a type of volcano usually built almost entirely of fluid lava flows. They are named for their large size and low profile, resembling a warrior's shield. This is caused by the highly fluid lava they erupt, which travels farther than lava erupted from more explosive volcanoes...

 located in Wrangell-St. Elias National Park and Preserve

Wrangell-St. Elias National Park and Preserve

Wrangell–St. Elias National Park and Preserve is a United States National Park in southeastern Alaska. It was established in 1980 by the Alaska National Interest Lands Conservation Act. The park area is included in an International Biosphere Reserve and is part of a UNESCO World Heritage Site...

 in southeastern Alaska

Alaska

Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...

, United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. The shield rises over 12000 feet (3,657.6 m) above the Copper River

Copper River (Alaska)

The Copper River or Ahtna River is a 300-mile river in south-central Alaska in the United States. It drains a large region of the Wrangell Mountains and Chugach Mountains into the Gulf of Alaska...

 to its southwest. Its volume is over 220 cubic miles (917 km³), making it more than twice as massive as Mount Shasta

Mount Shasta

Mount Shasta is located at the southern end of the Cascade Range in Siskiyou County, California and at is the second highest peak in the Cascades and the fifth highest in California...

 in California, the largest stratovolcano by volume in the Cascades

Cascade Range

The Cascade Range is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, and the notable volcanoes known as the High Cascades...

. It is part of the Wrangell volcanic field, which extends for more than 250 km across Southcentral Alaska into the Yukon Territory, and has an eruptive history spanning the time from Pleistocene to Holocene.

Modern Mount Wrangell, built upon the remnants of a mid-Pleistocene volcano, has an eruptive history spanning from 750,000 years ago to minor phreatic eruption

Phreatic eruption

A phreatic eruption, also called a phreatic explosion or ultravulcanian eruption, occurs when rising magma makes contact with ground or surface water. The extreme temperature of the magma causes near-instantaneous evaporation to steam, resulting in an explosion of steam, water, ash, rock, and...

s in 1884.
An ice-filled caldera

Caldera

A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption, such as the one at Yellowstone National Park in the US. They are sometimes confused with volcanic craters...

 2.5 by in diameter lies at the top of Wrangell's broad shield.