Portage Glacier sits at the head of Portage Lake, about 15 km southeast of Girdwood along the Seward Highway. The Begich, Boggs Visitor Center on the lake shore — a striking modernist building with a green-shingled roof — has excellent interpretive displays on glaciers, the 1964 earthquake, and the ecology of the Chugach National Forest. The Forest Service-run Ptarmigan tour boat sails six times daily in summer right up to the glacier face.
The drive along Portage Lake is itself spectacular: a single road threading between vertical walls of mountain and the milky-blue meltwater lake. The short trail to Byron Glacier, a few hundred metres from the visitor centre car park, takes you within touching distance of a smaller hanging glacier.
Beyond Portage is the tunnel to Whittier — the longest combined road-and-rail tunnel in North America — and the access to Prince William Sound boat trips. Allow half a day from Girdwood.