Huge concrete dams across steep, narrow canyons form canyon impoundments, the dominant type in the Southwest and West. These waters are the most capacious and deepest reservoirs, often over 200 feet. They’re also ultraclear, a result of the sand and rock that form the basin. These substrates yield little plant life, so cover is in the form of sparse stick-ups, boulders, and sheer canyon walls with occasional rock slides. Canyon impoundments are narrow and very long, with long tributary arms.

These oligotrophic impoundments typically feature a deep, oxygenated hypolimnion that supports stocked rainbow trout. Warmwater species like largemouth usually inhabit shallow bays and tributary arms, but large fish or schools of small bass may roam the open water, feeding on shad and the occasional trout.

Canyon bass fishing patterns are a study in contrasts. Many anglers catch bass by working plastic worms along deep breaks and shelves, sometimes taking bass in water over 50 feet deep. At the same time, canyon impoundments are known for great topwater fishing, with opportunistic fish rushing to the surface from deep shade to nail poppers and other baits. And while small soft plastics are commonly successful, lunker hunters employ giant plugs and soft plastic baits that imitate rainbow trout.

Due to low fertility and competition from striped bass for prey, largemouth bass don’t reach high density in many canyon impoundments. In some smaller western waters, however, stocking of Florida bass has yielded huge bass, threatening the world record in California.