Portage Glacier

Portage Glacier is one of the most-visited glaciers in Alaska, located 60 miles south of Anchorage in the Portage Valley — a dramatic mountain canyon at the head of Turnagain Arm. The glacier descends from the Chugach Mountains into Portage Lake, which is studded with house-sized icebergs calved from the glacier's face. The glacier has retreated significantly over the past century; it was visible from the road in 1990 but has since pulled back well beyond the sight line, meaning the glacier itself can only be seen by boat or from the Begich, Boggs Visitor Center — a 5-mile drive into the valley from the Seward Highway. The visitor center (free entry, $5 parking) houses exhibits on glacier formation, local wildlife, and the 1964 Great Alaska Earthquake, which caused severe land subsidence throughout the Portage Valley. The primary visitor activity is the Glacier Discovery cruise, operated from the visitor center dock by a park concessionaire; this 90-minute boat tour crosses iceberg-filled Portage Lake to reach the glacier face for close-up views. Ghost Forest, a stand of white snag trees visible from the valley road, marks trees killed by saltwater intrusion after the 1964 earthquake raised Turnagain Arm sea levels and flooded the valley floor. A short flat trail from the visitor center loops through the snag field along the lakeshore. Byron Glacier, a hanging glacier reached by a 1.5-mile round trip trail from a separate parking area 2 miles back toward the highway, provides a more intimate glacier canyon walk and is accessible without a boat fee.