Glacier Bay's ice began retreating from the Little Ice Age maximum around 1750. The rate has averaged about 100 feet per year - fast enough that single human lifetimes have witnessed dramatic change. John Muir's 1879 visit occurred when the ice still filled the upper bay; by his return in 1890, it had retreated further. The mechanism is straightforward: the bay's glaciers, fed by the same Fairweather Range that holds Alaska's highest coastal peak, have accumulated less ice than they've lost to calving and melting. The result is one of the fastest glacial retreats documented anywhere - 65 miles in 230 years, exposing a landscape from under the ice.

Seventeen tidewater glaciers remain in Glacier Bay, their fronts calving into the sea. Margerie Glacier, the most visited, regularly drops ice chunks the size of small buildings into the water; the resulting waves and thunder draw the cruise ship passengers who constitute most park visitors. Grand Pacific Glacier shares the inlet with Canada; the boundary runs through ice. The glaciers are remnants, holding on in the upper reaches while the lower bay has been ice-free for over a century. Each year brings more retreat; scientists monitor the movement as an indicator of broader climate trends. What took millennia to build is dismantling in decades.

The bay that didn't exist until recently now teems with life. Humpback whales return each summer to feed on krill and herring concentrated in the cold water; an encounter with bubble-net feeding whales is among Alaska's great wildlife experiences. Harbor seals haul out on ice floes at glacier fronts. Steller sea lions, harbor porpoises, and orcas patrol the waters. On land, the succession from bare rock to full forest takes roughly 200 years, visible in compressed distance as you travel from glacier front to bay mouth. The ecosystem that's built itself since the ice left demonstrates resilience; the speed of that building demonstrates how recently the ice was here.

The Huna Tlingit lived around Glacier Bay before the Little Ice Age advance drove them south. Their oral histories describe the ice's advance in detail that proved accurate when scientists later reconstructed the timeline. The retreat allowed return; Tlingit connections to the bay are cultural and spiritual as well as historical. The park now incorporates Indigenous interpretation; Huna Tribal House in Bartlett Cove provides cultural context. The partnership acknowledges what early park management denied: that this landscape has been homeland for people who understood its changes long before scientists arrived with instruments.

Glacier Bay National Park is accessible only by air or water from Juneau (65 miles). Cruise ships provide most visitor access; approximately 650,000 passengers enter the bay annually during summer. Independent travelers can fly to Gustavus (the park entrance community) or take the Alaska Marine Highway ferry. Day boats from Bartlett Cove offer tours to the glaciers. Kayaking provides independent access; rental and guided trips are available. Camping in the backcountry requires permits and bear-proof food storage. The park has limited facilities; Gustavus provides lodging and basic services. The experience is wilderness - genuine remoteness, guaranteed wildlife, and the sound of ice calving into water in a landscape that emerged from under glaciers within recent memory.