Within Glacier there's an almost unlimited range of fishing possibilities, with a catch-and-release policy encouraged. You can fish in most waters of the park, but the best fishing is generally in the least accessible spots. A fishing license is not required inside the park boundary, but you must stop by a park office to pick up a copy of the regulations. The fishing season runs from the third Saturday in May to November 30.
Fishing on both the North Fork and the Middle Fork of the Flathead River requires a Montana conservation license ($10) plus a Montana fishing license ($15 for two consecutive days or $60 for a season). They are available at most convenience stores, sports shops, and from the Montana Department of Fish, Wildlife, and Parks (406/752-5501).