ApproachFollow the Isberg Pass trail to the vicinity of Isberg Lakes, and follow a drainage up to the ridge between Isberg Peak and Long Mountain. Make a gradually descending traverse northeast, first past Harriet Lake, then around the west side of Foerster Peak. Cross a low saddle on the north shoulder of Foerster Peak, dropping down over talus to a small tarn/lake west of the peak.
This shoulder can also be reached by easy cross-country hiking from the vicinity of Foerster Creek along the Isberg Pass trail. This option is considerably longer (both mileage and time-wise) than the shortcut via Isberg Lakes.
Route DescriptionFrom the lake, ascend grassy slopes and then loose scree and talus up a chute to an obvious notch just east of the summit. (The notch also appears to be reachable from the north if approaching from the Lyell Fork, but would require axe/crampons year-round).
From the notch, guidebooks and trip reports paint a picture of a confusing, intricate route, but it is much more obvious than these descriptions make it sound. Traverse left into a chute, and follow this up to where difficulties increase. From here, traverse around to the right and make a gradually ascending counter-clockwise spiral up to the summit.