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Lees Ferry (also known as Lee's Ferry, Lee Ferry, Little Colorado Station and Saints Ferry) is a site on the Colorado River in Coconino County, Arizona in the United States, about southwest of Page and south of the Utah–Arizona border. Due to its unique geography – the only place in hundreds of miles from which one can easily access the Colorado River from both sides – it historically served as an important river crossing and starting in the mid-19th century was the site of a ferry operated by John Doyle Lee, for whom it is named. Boat service at Lees Ferry continued for over 60 years before being superseded by a bridge in the early 20th century, which allowed for much more efficient automobile travel. Lees Ferry served as a military outpost for 19th-century settlements in Utah, a center of limited gold seeking and since the 1920s the principal point at which river flow is measured to determine water allocations in the Colorado River basin. Lees Ferry demarcates the boundary between the Upper and Lower Basins of the Colorado River; the states which make up each basin are legally allocated one-half of the river's natural flow. Glen Canyon Dam impounds the Colorado a short distance upstream and completely regulates the river flow past Lees Ferry. Lees Ferry has long been a focal point of American Southwest water disputes, and has been called "both the physical and spiritual heart of water history in the arid West". Today Lees Ferry is a well-known fishing and boat launching point, including for whitewater rafting trips through the Grand Canyon. ==Geography and geology== Lees Ferry is located in northern Arizona, at the point where the Paria River joins the Colorado from the north. Lying in an open valley directly downstream from Glen Canyon and shortly above Marble Canyon (the uppermost section of the Grand Canyon), it is the only place in more than where the Colorado is not hemmed in by sheer canyon walls. This made it an important crossing point before the construction of Navajo and Glen Canyon Bridges in the 20th century.〔(【引用サイトリンク】title= Lees Ferry: Crossing the Colorado River )〕 Here, the Colorado River is also much smoother and calmer than the stretches that lie above and below. In the past, another crossing was the former Glen Canyon reach, but it is now flooded under Lake Powell, formed by Glen Canyon Dam upstream. Lees Ferry is designated within the southwesternmost extreme of Glen Canyon National Recreation Area and is considered the northernmost end of Grand Canyon National Park. It lies upstream of the Colorado's mouth at the Gulf of California, at the approximate halfway mark of the river's length. The surrounding valley formed because of a swell in the underlying rock of the Colorado Plateau that caused the regional elevation to intersect the Chinle and Moenkopi Formations, deposited in the Triassic about 208–245 million years ago. This area contains sandstone, siltstone, shale and limestone formed by the sediments on ancient seabeds and later alluvial deposits made by the Colorado and Paria Rivers. Because these are more easily eroded than the rock layers that lie above and below them, the Colorado Plateau gradually slopes down to river level at Lees Ferry through a series of flat benchlands. 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「Lee's Ferry」の詳細全文を読む スポンサード リンク
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