Tributary

An "early tributary" is a tributary that joins the main stem river closer to the main river's source than its end. Similarly, a "late tributary" joins the main river much further downstream, closer to the main river's end point.

Forks are sometimes designated as right or left. Here, the "handedness" is from the point of view of an observer facing upstream. For instance, Steer Creek has a left tributary which is called Right Fork Steer Creek.