The Dietrich River is a 35 miles (56 km) long braided river in the Yukon-Koyukuk Census Area of Alaska.

It flows south to join the Bettles River and to form the Middle Fork Koyukuk River.

[1] The river forms a broad floodplain.

Common species of fish found in the river include Arctic grayling, burbot, Dolly Varden trout, and whitefish.

This article related to a river in Alaska is a stub.