Many trout live in just a short stretch of stream—we call this home area a trout’s habitat. Trout need just a few basic things to survive: cold water, clean water, food to eat, places to hide from predators, and clean gravel to lay their eggs in. All the land around a stream that drains into a stream is called that stream’s watershed. Trout are affected by what happens in their whole watershed, because something that happens on the land can change one of those things they need in their stream habitat. Let’s take a closer look at streams, water, and watersheds.