Usk (Ktunaxa: ʔa·q̓anq̓unaʔwuʔk ) (Salish: čɫĺq̓ʷo ) is an unincorporated community in Pend Oreille County, Washington, United States. Usk is located along the Pend Oreille River 2 miles (3.2 km) southeast of Cusick. Usk has a post office with ZIP code 99180. It is part of the Kalispel Indian Reservation.Usk was named for the River Usk in Wales around 1890.