If you enjoy presenting terrestrial insect patterns on meadow streams, this time of year the park offers an unmatched variety of quality waters for doing so. Starting in the southwest corner, all Fall River Basin (Bechler, & Fall Rivers, Boundary & Mountain Ash Creeks) streams have meadow reaches full of ants, beetles, crane flies, and grasshoppers and not many fly-fishing visitors. The same insects prevail in the meadow stretches on Duck Creek and the Gibbon River, and the “Grasshopper Bank” on the Madison River was named for good reason. Do Firehole River trout a favor and try elsewhere until late September cools waters to their comfort. Now that the big stonefly events have moved through the Black Canyon of the Yellowstone River, terrestrial insect patterns bring the big interest from trout as they do on the Gardner River meadow sections. Not to be outdone, the northeast corner of the park offers almost a many quality meadow streams as Fall River Basin, but in a more crowded manner. Lamar River and Slough and Soda Butte Creek offer roadside convenience as well as upstream isolation. To the south, Lewis River meadow sections and the Snake River around and above the south entrance offer the same.
Certainly aquatic insect activity attracts trout on all these waters with such as AM spinner falls, daytime PMD & speckled dun emergences and some afternoon caddis activity. But you can bet on those big fish lurking in undercuts and beneath well-vegetated banks waiting for that unfortunate terrestrial guy drifting by and a resulting take!