Ugashik River, Brook in Lake and Peninsula, United States.

The Ugashik River runs 43 miles (69 km) west from the Ugashik Lakes group to Ugashik Bay, an estuary of Bristol Bay in the Bering Sea. The King Salmon and Dog Salmon rivers join near its mouth, and Dago Creek enters about 4 miles (6 km) from Smoky Point, where Ugashik Bay meets Bristol Bay.

The name Ugashik derives from early spellings such as Oogashik and Ougashick, which point to the river's source: two lakes and its muddy character. The river flows 43 miles (69 km) from near Lower Ugashik Lake into Ugashik Bay, an estuary of Bristol Bay. Pilot Point sits at its mouth.

The name Ugashik likely derives from early spellings Oogashik and Ougashick, suggesting 'two waters' (the lakes) and the river's muddy character. Pilot Point, a community at the river's mouth, relies on the river for salmon fishing and as a travel route. A salmon-counting weir operated by the Alaska Department of Fish and Game stands between Lower Ugashik Lake and a small lagoon.

The location is isolated and requires flying or boating to reach it. Visitors should prepare for cold water and changeable weather conditions.

Two major tributaries merge near the mouth and create especially productive fishing areas. This meeting point is known for its rich fish populations and draws fishers from the surrounding region.