Begin from the Glacier Gorge parking area, and don show shoes or skis as necessary. Follow the line of the summer trail to the Shortcut, but don't take the Shortcut. Turn right (west) and follow an unnamed drainage (usually tracked) until it is easy to veer south and gain the main trail near the Loch Vale Trail junction. Proceed west and take all the left branches in the trail. Follow the general line of the summer trail to the log bridge across Glacier Creek, stay right and follow the creek to Mill's Lake. Head south across the frozen lake (normally safe until May) and continue across Jewell Lake, beyond which the valley bottom can be followed all the way to Black Lake. Look for a large boulder on the left side of the trail maybe 100 yards past Jewell Lake. Go straight west over/around windfall and across Glacier Creek. The ice flow will be obvious about 200 feet above the creek.