Hi rpm,
Have you seen this website:
http://www.wrangellsteliaspark.com/index.html ?
It gives info on quite a few backpacking routes and has a link to purchase their guidebook. They list "Frontcountry" routes with trailheads accessible by road, and "Backcountry" routes that require a flight in.
I don't know anything about backpacking there, but I've been on climbing trips there twice. If your route doesn't require flying in, at least try to swing a flightseeing excursion before or after your trip. That's the largest mass of ice outside of the polar regions and the views of the glaciers and peaks are incredible! Almost as awe-inspiring as the views from the Mount Whitney summit ridge (there's the Whitney connection).