The crux of this route is the approach. Bring your best route finding skills with you. It would be hard to describe so I've included a few photos. Basically, from White Pass, on the PCT, hike the Foam Creek trail for 1 1/2 to 2 miles. Cross the ridge at a knoll to the North and cross the basin in front of you to reach Glacier Gap.
You have to zig and zag, up and down, over a lot of snowy terrain.
Located on the South east side of Glacier Peak. The route starts at Glacier Gap. Most people approach from White Pass on the PCT, and the Foam Creek trail. I hiked in to White Pass on the Little Wenatchee River Trail and the Pacific Crest Trail. A total of 14 miles, more or less. The trails change yearly. Check with the Wenatchee rangers for current info.