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Balch Creek is a tributary of the Willamette River in the U.S. state of Oregon. Beginning at the crest of the Tualatin Mountains (West Hills), the creek flows generally east down a canyon along Northwest Cornell Road in unincorporated Multnomah County and through the Macleay Park section of Forest Park, a large municipal park in Portland. At the lower end of the park, the stream enters a pipe and remains underground until reaching the river. Danford Balch, after whom the creek is named, settled a land claim along the creek in the mid-19th century. After murdering his son-in-law, he became the first person legally hanged in Oregon. Basalt, mostly covered by silt in the uplands and sediment in the lowlands, underlies the Balch Creek watershed. The upper part of the watershed includes private residential land, the Audubon Society of Portland nature sanctuary, and part of Forest Park. Mixed conifer forest of Coast Douglas-fir, western redcedar, and western hemlock with a well-developed understory of shrubs and flowering plants is the natural vegetation. Sixty-two species of mammals and more than 112 species of birds use Forest Park. A small population of coastal cutthroat trout resides in the stream, which in 2005 was the only major water body in Portland that met state standards for bacteria, temperature, and dissolved oxygen. Although nature reserves cover much of the upper and middle parts of the watershed, industrial sites dominate the lower part. Historic Guild's Lake occupied part of the lower watershed through the 19th century, and in 1905 city officials held the Lewis and Clark Centennial Exposition there on an artificial island. After the exposition, developers converted the lake and its surrounds to industrial use, and in 2001 the Portland City Council declared the site to be an "industrial sanctuary". ==Course== Balch Creek begins in the Forest Park neighborhood in unincorporated Multnomah County near the intersection of Northwest Skyline Boulevard and Northwest Thompson Road at the crest of the West Hills. It flows generally east about to its confluence with the Willamette River, a major tributary of the Columbia River. The creek drops from above sea level at its source to at its mouth, a total of .〔〔 Most of this occurs in the first . In the hills, the stream gradient (slope) generally ranges from 15 to 30 percent interspersed with sections of less than 15 percent along the middle reaches. From its source, the creek runs east on private property near Forest Park, a large municipal park in Portland, before turning briefly south about from the mouth. Soon thereafter, the stream receives an unnamed tributary on the right bank and turns southeast on private property along Northwest Cornell Road. It enters the city and the Audubon Society of Portland simultaneously about from the mouth, receives two more unnamed tributaries on the right, and flows northeast, entering the part of Forest Park known as Macleay Park. For about the creek parallels Wildwood Trail, the main hiking trail in Forest Park, until reaching a former public restroom known as the Stone House.〔 From here Balch Creek runs beside the Lower Macleay Trail, another hiking trail, for about . Near Northwest Thurman Street, roughly from the mouth, the creek flows through a trash rack into an diameter storm sewer.〔 City workers first diverted the creek into a pipe in the early 20th century. The water empties into the Willamette River in the city's Northwest Industrial neighborhood at Outfall 17. About below this outfall, the Willamette enters the Columbia River.〔 The map includes river mile markers along the Willamette.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Balch Creek」の詳細全文を読む スポンサード リンク
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