Climber's Guide to Glacier National Park
By J. Gordon Edwards. Excellent guidebook--exhaustive and detailed, yet concise. Also the only guidebook, making it a must-buy. Make sure you buy the 1995 edition.
Our fourth hike in Glacier was a through-hike from Logan Pass to Many Glacier, via Swiftcurrent Pass. Something like 15 miles, though with not a terrible amount of elevation gain. The drop into Many Glacier was mind-numbing!