a river in Arkhangel’sk Oblast, RSFSR, a right tributary of the Mezen’ River. It is 363 km long and drains an area of 15,100 sq km. Originating in the Timan Range, it flows through a broad valley. The Peza is fed primarily by snow. The mean flow rate is approximately 130 cu m per sec, with a maximum of more than 2,500 cu m per sec. The river freezes in November, and the ice breaks up in the first half of May. The Peza is used for floating timber and is navigable during spring high water for a distance 300 or 320 km from the mouth. The basin contains many lakes.