Areas at the downstream end of riffles serve as critical feeding areas for juvenile trout. Riffles typically have the highest aquatic insect biomass, density, and diversity, so young trout find an abundance of food.

Pools are critical for trout. One of their most important functions is to provide adult holding habitat, places where trout can rest for days or weeks prior to spawning. Even when they are not spawning, big trout use deep pools as havens. Pools also serve as overwinter-rearing habitat for juvenile trout and as thermal refuge for trout of all ages. Their depth tends to moderate water temperatures in winter and summer.

Trout spawning habitat is often found in the transition zone between pools and riffles (in areas known as glides). Trout eggs need clean, oxygen-rich water flowing over and through gravel, conditions met in glides and at the head of riffles.

The "fry stage" is when a juvenile trout has absorbed its yolk sac and leaves the gravel of the redd. Fry habitat for most trout is closely associated with the shallow edges of streams and low velocity side-channels. Fry and juvenile trout also use areas with high levels of shade, undercut banks, and lots of large woody debris.