[3] It begins near Imuruk Lake on the Seward Peninsula and flows generally north to Kugruk Lagoon, at Kotzebue Sound on the Chukchi Sea.

[1] The river enters the lagoon 5.5 miles (8.9 km) southeast of Cape Deceit in the Northwest Arctic Borough.

[1] Some mining was reported on Windy, Neva, North Fork, Coarse Gold, Henry, Taylor, and Macklin creeks, tributaries of the Kugruk River.

The bed rock along the Kugruk River is generally highly metamorphosed, consisting of mica-schists and calcareous schists, with large intrusions of greenstone.

[3] North Fork is a large tributary of the Kugruk River from the east, about 10 miles (16 km) above Windy Creek.

[3] Coarse Gold Creek is a large tributary of the Kugruk River from the west side, about a mile above North Fork.

It heads in the high divide between the Kugruk and Agiapuk drainages, and flows eastward, cutting across the strike of the schists and limestones.

It heads in the high divide south of Kugruk Mountain, and flows eastward in a deep canyon cut in the upland and across the strike of the schist and limestone bed rock.

[3] This article incorporates text from this source, which is in the public domain: A. J. Collier's "A Reconnaissance of the Northwestern Portion of Seward Peninsula, Alaska" (1902)