Yellowstone Park is not merely a land of geysers and grizzly bears. Three famous trout rivers–the Madison, Yellowstone, and Snake–have their beginnings in the park, and dozens of smaller streams also hold trout, as well as over 100 lakes. The fishing is so vast and varied that any level of angler can catch fish.
The only trout native to the park is the aptly named Yellowstone cutthroat, a beautiful green, black-spotted fish with a pair of almost fluorescent red slashes under its jaw. Not only pretty, cutthroats are relatively easy to catch, especially on flies.
Yellowstone “cutts” are found in almost every stream within the park but are most numerous in the Yellowstone River between Yellowstone Lake and the Grand Canyon of the Yellowstone, where high waterfalls have kept the upper river free of nonnative rainbow, brown, and brook trout that inhabit the lower river. Flyfishing for large cutthroats is especially good in the stretch of river called Buffalo Ford–and you’ll usually see lots of bison in the area. Keep at least 100 yards away, especially from mature bulls and cows with calves, and you won’t have a problem.
The Madison is regarded as more of an expert’s stream, partly because almost all of its trout are harder-to-catch browns and rainbows. While any decent trout fly will catch cutthroats, consult one of the fly shops in nearby West Yellowstone about fishing the Madison. These shops can also provide guides who know the river well.
The Madison’s main tributary, the Firehole, can also be pretty “technical,” but because it rises from springs in the geyser basin around Old Faithful, its warmer waters remain clear even in early summer, when other Yellowstone streams are murky with runoff. The other Madison tributary, the Gibbon, is a much friendlier freestone stream, easily reached by road almost anywhere along its length. Other notable smaller trout streams are Slough Creek, and the Lamar and Gardiner Rivers.
There’s also excellent lake fishing. Yellowstone Lake holds both native cutthroats and illegally planted lake trout (you can keep all the lakers you want). Shoshone Lake has browns and rainbows, along with a few cutthroats and brook trout, whereas Lewis Lake is noted for big browns. Maps of the park are available at any ranger station, along with fishing licenses: $5 for seven days or $10 for the season. All boats used in the park (even float tubes) also require a similarly priced license.