Two major tributaries account for nearly 60% of inflow by streams or rivers into Utah Lake. The Provo River accounts for 36% of the inflow, and the Spanish Fork river accounts for 24%. Other tributaries include the American Fork river, Current Creek, Dry Creek, Hobble Creek, and Mill Race Creek. Additionally, there are many hot springs and smaller creeks flowing into the lake. Utah Lake is drained by the Jordan River, which begins at the lake's north end. The river flows north through Utah, Salt Lake, and Davis counties and then into the southeast portion of the Great Salt Lake. Given the lake's semi-arid climate, large surface area, and shallow average depth, evaporation accounts for 42% of Utah Lake's outflow.