Tigris–Euphrates river system through the central plain and combine at Al-Qurnah to form the Shatt al-Arab and discharge into the Persian Gulf. The region has historical importance as part of the Fertile Crescent region, in which civilization is believed to have first emerged. The ecoregion is characterized by two large rivers, the Tigris and Euphrates. The rivers have several small tributaries which feed into the system from shallow freshwater lakes, swamps, and marshes, all surrounded by desert. The hydrology of these vast marshes is extremely important to the ecology of the entire upper Persian Gulf. Historically, the area is known as Mesopotamia. As
Malheur River Malheur River The Malheur River (local pronunciation: "MAL-hyure") is a tributary of the Snake River in eastern Oregon in the United States. It drains a high desert area, between the Harney Basin and the Blue Mountains and the Snake. Despite the similarity of name, the river does not flow into nearby Malheur Lake, which is located in the enclosed Harney Basin southwest of the watershed of the river. When water levels were higher, Malheur Lake would drain into the Malheur River. The Malheur River rises in the southern Blue Mountains of southern Grant County, south of Strawberry Mountain in the