Two centuries ago, a single massive glacier filled the entirety of Glacier Bay.

Countries & Cities · Published 15 October 2026 · Updated 25 October 2026 Swipe more like this →

In short: Today, Glacier Bay is a 65-mile-long fjord, but it was once dominated by the Grand Pacific Glacier. As this colossal ice sheet retreated, it fractured into 20 separate glaciers. Eleven of these remain as active tidewater glaciers, periodically calving massive blocks of ice into the frigid Alaskan waters.

Located in southeastern Alaska, Glacier Bay National Park and Preserve encompasses over 5,000 square miles of rugged terrain. The landscape is defined by its dramatic transition from sea to summit, including the 15,300-foot Mount Fairweather. The region's history is one of rapid geological change; as recently as 200 years ago, the entire bay was occupied by the Grand Pacific Glacier, which measured over 4,000 feet in thickness and 20 miles in width. As the ice retreated, it exposed a landscape now characterized by moss-covered moraines, coastal rainforests, and alpine tundra.

The park serves as a sanctuary for a diverse array of wildlife, including brown and black bears, wolves, mountain goats, and moose. It also provides critical protection for endangered species like the humpback whale and threatened populations of Steller sea lions and spectacled eiders. This ecological richness is managed in collaboration with the Huna and Yakutat Tlingit, who consider the area their homeland. The park's dynamic nature is further evidenced by post-glacial rebound, a process where the land physically rises as the immense weight of the ancient ice is removed.

Access to this remote wilderness is limited to boat or plane, with the only road connecting the town of Gustavus to the park headquarters at Bartlett Cove. Visitors often arrive by cruise ship to witness the calving of tidewater glaciers, where ice blocks up to 200 feet high crash into the bay. Because of the sheer volume of ice displaced during these events, ships must maintain a distance of at least two miles from glaciers like the Johns Hopkins. This constant state of flux makes the park a unique laboratory for observing vegetation returning to land long held by ice.

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