Pinguk River (alternate Iñupiaq language name, Pinauk meaning "hill")[2] is a waterway located on the Seward Peninsula in the U.S. state of Alaska.

The geological formation reported in the valley consists of slate and is exposed in some stretches of the river.

The river bed is strewn with gravel and pebbles of slate and limestone.

[3] The McKillop branch has its source in the limestone hills, which are an eastern arm of the York Mountains.

[3] The York River, a branch of the Pinguk River, which rises in the Brooks Mountain, is reported to be rich in tin deposits in its head reaches in the mountains.