Fisheries biologists often talk about quality aquatic habitat in terms of the "Four C's": Cold water temperatures for successful trout spawning and rearing; Clean stream substrates for successful fish spawning and egg incubation; Complex habitat features for adequate fish cover and food availability; and Connected habitats to allow movement of fish among various habitats during different life-history stages. The Four C's also benefit other organisms, everything from aquatic insects to the birds and mammals that utilize aquatic habitats. Cold, clean, complex, and connected should be the mantra of everyone concerned with stream conservation in the Northern Rockies.