Byron Glacier

This very popular glacier lies just beyond the end of a flat, well-maintained trail up a narrow, glacier-scoured valley south of the Portage Lake. Byron descends from the same ice field that feeds both Portage Glacier on the lake and Blackstone Glacier in Prince William Sound. The approach is a real-time demonstration of how an ecosystem rebounds from the ice age, with large trees and forest giving way to alder thickets, which in turn morph into lichen-dotted rock only recently exposed by retreating ice. The upper valley is rugged and raw—with silt-blackened debris covering ice—offering an austere feel for authentic glacial terrain, as though you were on an adventure deep in Alaska’s coastal backcountry. Once snow has melted back, tiny, thread-like ice worms can be found on the lower slopes of exposed ice, concentrated on the glacier’s algae-strewn “dirty” surface. Byron may be the easiest spot in the world to view ice worms in the wild.

How To View

During summer, hike about one mile up the Byron Glacier Trail to an open flat with exposed boulders and channels of Byron Creek. Two colossal ice cones created by snow avalanches hug the eastern walls of the valley, sometimes showing off dramatic ice caves formed by meltwater streams. Depending upon how much it avalanched during the previous winter, the closest cone might also straddle the creek, which then carves out its own, new cavern. (Do not attempt to enter these ice caves—hunks can fall without warning!) A remnant of Byron lies buried beneath a large rock glacier of boulders and silt, rising above the creek and blocking a view of the upper valley. Byron’s exposed terminus is a quarter mile further up. If you want to experience ice worms, return to the valley at solar dusk, which can be as late 9 pm to 11 pm in near the solstice in June. The worms will surface once all sign of the sun is gone, and light grows dim.

Winter travel up Byron Valley is not recommended for most people. Avalanches regularly overrun the valley bottom.

Getting There

Latitude: 60.744523
Longitude: -148.856062

Head south from Anchorage on the Seward Highway to the head of Turnagain Arm. Turn east on the Portage Glacier Road and drive about five miles to the shore of Portage Lake. Continue south on the road as it curves around the lake toward the mountains. The trailhead for the 1-mile Byron Glacier Trail is just over .6 miles ahead on the right.