We set off on the Bonanza Mine Trail, 9 miles round trip, with 3800ft elevation gain ahead of us. It starts out steep, and then gets steeper. The reward comes when the trail emerges from the tree line, just past 2 miles in, onto a ridge that provides a panoramic view over the Kennecott Glacier moraines. The mine site itself is pretty spectacular. An old bunkhouse sits against the slope, just under the ridge. You can hike up further onto and along the ridge for even better views of the valley, including a glimpse of Root Glacier.
Beyond the boulders is a beautiful alpine glen. Stay to the left of the creek and follow the trail over a crest to Lower Reed Lake, strikingly turquoise-colored and flanked by rugged, rocky escarpments disappearing into the clouds at an elevation of about 4000ft.
On the spectrum of Alaskan trails, Portage Pass is likely one of the highest ranking in terms of reward v. effort. Starting in Whittier, the trail connects through to Portage Lake, delivering spectacular views of Portage Glacier that you would otherwise have to take a ferry to experience.