Fishing Glacier National Park by Russ Schneider
"Russ Schneider, author and outdoor guide, has compiled information on 64 bodies of water in the park and on the North and Middle Forks of the Flathead River....The book leads you to streams and lakes where you'll find kokanee salmon, mountain whitefish, artic grayling, and trout."
I used this book almost exclusively when I researched fishing in Glacier National Park. In fact, you will find only a few books on the subject. If you are just going to do some incidental fishing in Glacier National Park, and you only plan on staying three or four days, then I believe my Glacier National Park category on fishing will be all you need. However, if you plan on hiking and camping in the park, be sure to purchase this book.