Madison River in Yellowstone National Park Professional Review and Guide
"Looks so easy, but it ain’t. From the junction of the Gibbon and Firehole Rivers, the Madison River flows happily along the park’s west entrance road for about 14 miles. A drive along the road will show you elk, an occasional moose, anglers casting for browns and rainbows, a grizzly (on rare occasions), and other forms of wildlife indigenous to the park. These waters have been fished from the days that the idea for the park was hatched around a campfire at the head of the Madison in 1872.
Then, the primary species was grayling. Just a good hoot and holler from West Yellowstone, with more fly fishing shops per block than any other tourist town in the west, the park section of the Madison sees more than its share of fishing pressure. Make no mistake, though, this is productive water. Rich in dissolved minerals from its geothermally bred headwaters, the aquatic vegetation and insects thrive in the upper reaches. Species: Brown, rainbow. Angling methods: fly-fishing only."