Dairy Creek (Oregon)

Dairy Creek
Dairy Creek just south of the Tualatin Valley Highway
Location of the mouth of Dairy Creek in Oregon
EtymologyProbably first used by Hudson's Bay Company employees who ran a dairy near the creek prior to 1840.
Location
CountryUnited States
StateOregon
CountyWashington
Physical characteristics
SourceConfluence of East Fork Dairy Creek and West Fork Dairy Creek
 • locationnear Schefflin, Washington County, Oregon
 • coordinates45°34′11″N 123°04′22″W / 45.56972°N 123.07278°W / 45.56972; -123.07278
 • elevation151 ft (46 m)
MouthTualatin River
 • location
near Hillsboro, Washington County, Oregon
 • coordinates
45°30′06″N 122°59′43″W / 45.50167°N 122.99528°W / 45.50167; -122.99528
 • elevation
128 ft (39 m)
Length10.55 mi (16.98 km)
Basin size226 sq mi (590 km2)
Discharge 
 • locationEast Fork Dairy Creek, 12.3 miles (19.8 km) above confluence with West Fork Dairy Creek
 • average76.9 cu ft/s (2.18 m3/s)
 • minimum6.9 cu ft/s (0.20 m3/s)
 • maximum1,580 cu ft/s (45 m3/s)

Dairy Creek is a 10.55-mile (16.98 km) tributary of the Tualatin River in the U.S. state of Oregon. It begins at the confluence of its east and west forks near the unincorporated community of Schefflin and meanders southeast across the Tualatin Valley to the Tualatin River near Hillsboro, in Washington County. East Fork Dairy Creek begins at 45°47′18″N 123°02′29″W / 45.788446°N 123.041498°W / 45.788446; -123.041498 (Dairy Creek East Fork source) in Columbia County, slightly north of its border with Washington County, and flows generally south for 22 miles (35 km). West Fork Dairy Creek, also about 22 miles (35 km) long, forms at 45°45′19″N 123°10′41″W / 45.7553899°N 123.178168°W / 45.7553899; -123.178168 (Dairy Creek West Fork source), near the unincorporated community of Tophill, and flows generally southeast. Before railroads displaced river boats on the Tualatin, some steamships also worked the lower section of Dairy Creek, with plans to go as far up stream as Centerville.