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The Columbia River Gorge is a canyon of the Columbia River in the Pacific Northwest of the United States. Up to deep, the canyon stretches for over as the river winds westward through the Cascade Range forming the boundary between the State of Washington to the north and Oregon to the south. Extending roughly from the confluence of the Columbia with the Deschutes River down to eastern reaches of the Portland metropolitan area, the water gap furnishes the only navigable route through the Cascades and the only water connection between the Columbia River Plateau and the Pacific Ocean. The gorge holds federally protected status as a National Scenic Area called the Columbia Gorge National Scenic Area and is managed by the Columbia River Gorge Commission and the US Forest Service. The gorge is a popular recreational destination. ==Description== The Columbia River, Klamath River in Northern California, and Fraser River in Southern British Columbia are the only three rivers connecting the east-side watersheds of the Cascade Mountain Range to the Pacific Ocean. Each river has created a gorge through the Cascade Mountain Range. The Columbia River Gorge marks the state line between Oregon and Washington. The wide range of elevation and precipitation makes the Columbia River Gorge an extremely diverse and dynamic place. Ranging from to sea level, and transitioning from of precipitation to only in , the Gorge creates a diverse collection of ecosystems from the temperate rain forest on the western end—with an average annual precipitation of —to the eastern grasslands with average annual precipitation between , to a transitional dry woodland between Hood River and The Dalles. Isolated micro-habitats have allowed for many species of endemic plants and animals to prosper, including at least 13 endemic wildflowers. The Gorge transitions between temperate rainforest to dry grasslands in only 80 miles, hosting a dramatic change in scenery while driving down I-84. In the western, temperate rainforest areas, forests are marked by bigleaf maples, Douglas Fir, and Western hemlock, all covered in epiphytes. In the transition zone (between Hood River and The Dalles), vegetation turns to Oregon white oak, Ponderosa pine, and cottonwood. At the eastern end, the forests make way for expansive grasslands, with occasional pockets of lodgepole pine and Ponderosa pine. Atmospheric pressure differentials east and west of the Cascades create a wind tunnel effect in the deep cut of the gorge, generating 35 mph (56 km/h) winds that make it a popular windsurfing and kitesurfing location. The Gorge is a popular destination for hiking, biking, sight-seeing, fishing, and watersports. The area is known for its high concentration of waterfalls, with over 90 on the Oregon side of the Gorge alone.〔("Columbia River Gorge of Oregon" ). Northwest Waterfall Survey. Retrieved February 6, 2011.〕 Many are along the Historic Columbia River Highway, including the notable -high Multnomah Falls. Trails and day use sites are maintained by the Forest Service and many Oregon and Washington state parks. 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「Columbia River Gorge」の詳細全文を読む スポンサード リンク
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