Portage Glacier retreated three kilometres between 1914 and 1995, carving Portage Lake in its wake and creating the only tidewater glacier accessible by paved road from Anchorage. The Begich Bogsjos Visitor Center, completed in 1986, was originally built at lake's edge to offer direct views of the glacier's face. Within a decade, the ice had withdrawn so far that boat access became the sole way to witness calving events up close. Today, Portage Glacier remains one of Alaska's most visited ice formations, drawing over 300,000 annual visitors to the Chugach National Forest. The glacier descends from the Portage Pass névé field at roughly 1,800 metres elevation, spilling into the lake through a narrow valley flanked by hanging glaciers on Burns and Byron peaks. Calving occurs intermittently throughout the day as meltwater lubricates the terminus, sending house-sized fragments into the lake with a sound like distant artillery. The ice itself appears cobalt blue in cross-section, a product of air-free compression over centuries. Black bears forage the shoreline in late summer, and Dall sheep graze the scree slopes above the treeline, visible through binoculars from the boat deck. Portage Valley sits within a maritime-influenced microclimate that funnels moisture from Prince William Sound, producing annual snowfall exceeding ten metres at higher elevations. This precipitation feeds not only Portage Glacier but also the dozen smaller ice tongues visible from the lake, including Middle, Byron, and Shakespeare glaciers. The valley floor, scoured to bedrock during the Pleistocene, now supports alder thickets and fireweed, which bloom magenta in July. Bald eagles nest in the cottonwoods near Portage Creek, and harbour seals occasionally swim upriver from Turnagain Arm during high tides. The portage glacier cruise and wildlife explorer tour operates year-round, though summer months offer the longest daylight and highest probability of wildlife sightings along the watershed.