a river in Tiumen’ Oblast, RSFSR; a right tributary of the Ob’ River. The Trom”egan is 581 km long and drains an area of 55,600 sq km. The river rises in the Siberian Uvaly and empties into the Sanin watercourse. It is fed by mixed sources but mainly by snow. Its high water is from May through October. The mean flow rate of the Trom”egan is 425 cu m per sec. The river freezes in October or early November, and the ice breaks up in May. Its main tributary is the Agan River, which flows into the Trom”egan from the left.