Туалатин өзені: Орегонның фермерлік аймағы мен табиғи қорықтары

The Tualatin River is a tributary of the Willamette River in Oregon in the United States. The river is about 83 mile (134 km) long, and it drains a fertile farming region called the Tualatin Valley southwest and west of Portland at the northwest corner of the Willamette Valley. There are approximately 500,000 people residing on 15 percent of the land in the river's watershed.

The Tualatin River arises near Windy Point on the eastern side of the Northern Oregon Coast Range. It begins in the Tillamook State Forest in Washington County and flows about 83 mile (134 km) to the Willamette River near West Linn in Clackamas County. Along the way, it falls from about 2000 feet (610 m)

From its source, the river flows south for about 1 mile (2 km) before turning east to parallel to Blind Cabin Ridge, which is to the river's right. Shortly thereafter, the river plunges over the 40 feet (12 m) Ki a Kuts Falls, then receives Maple Creek from the left and then Sunday Creek, also from the left, at river mile (RM) 76.7 (RK 123.4). Lee Creek enters from the left and Patten Creek from the right before the river reaches Hillsboro Reservoir and then Haines Falls at about RM 73 (RK 117). Hillsboro Reservoir Road and Southwest Lee Falls Road run roughly parallel to the river along its left bank from the reservoir to the unincorporated community of Cherry Grove. Over the next stretch, the river runs roughly parallel to Hagerty Ridge, which is on the right. About 2 mile (3 km) further downstream, the river goes over Lee Falls and, shortly thereafter, Little Lee Falls before reaching Cherry Grove, which is on the river's left at the west end of Patton Valley. At Cherry Grove, the river passes under Roaring Creek Road, receives Roaring Creek from the right, passes under Bruce Road and Southwest S Road, and receives Hering Creek from the left. Thereafter, it flows under Northwest Mount Richmond Road and receives Mercer Creek from the left about 65 mile (105 km) from the river's mouth. Below this, Black Jack Creek enters from the left, and the river passes under Oregon Route 47 and flows by the city of Gaston, which is to the right.

The Tualatin River was named by the local Native American band, the Atafalati, that lived in the Tualatin Valley. The valley of the Tualatin was an important early farming region in the settlement of Oregon. The building of Canyon Road, a plank road to the Tualatin Valley from Portland, in 1856 is considered by historians to be one of the main reasons for Portland's rise as the dominant city in the region. The valley contains many natural wetlands, some of which have been designated the Tualatin River National Wildlife Refuge, and others are protected at Jackson Bottom Wetlands Preserve.

The drainage area of the river is approximately 712 square miles (1,844 km2) with 27 creeks feeding into the Tualatin. Its watershed is 15 percent urbanized, 35 percent agricultural, and 50 percent forested. It was the first river in the state to fail overall pollution limits.