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The Little Colorado River is a tributary of the Colorado River in the U.S. state of Arizona, providing the principal drainage from the Painted Desert region. Together with its major tributary, the Puerco River, it drains an area of about in eastern Arizona and western New Mexico. Although it stretches almost ,〔 only the headwaters and the lowermost reaches flow year-round. Between St. Johns and Cameron, most of the river is a wide, braided wash, only containing water after heavy snowmelt or flash flooding. The lower of the Little Colorado forms one of the largest arms of the Grand Canyon, at over deep where it joins the Colorado near Desert View in Grand Canyon National Park. ==Course== The river rises as two forks in the White Mountains of mid-eastern Arizona, in Apache County. The West Fork starts in a valley on the north flank of Mount Baldy at an elevation of nearly , while the East Fork starts nearby. The forks meet in a canyon near the town of Greer, forming the main Little Colorado River. It flows into River Reservoir, then leaves the canyon near Eagar. The river then turns north, meandering through Richville Valley, before emptying into Lyman Lake, impounded by an irrigation dam built in 1912. From there the river continues north, past the town of St. Johns. Shortly afterwards, the river transforms from a perennial stream to an ephemeral wash as it travels northwestwards through Hunt Valley, where it receives the Zuni River, then receiving Silver Creek and the Puerco River—its main tributaries—near the town of Holbrook as it flows into the Painted Desert. The Little Colorado passes Joseph City and crosses the Southern Transcon route of the BNSF Railway (originally the Atchison, Topeka and Santa Fe Railroad), now winding north into Coconino County. The river enters the Navajo Indian Reservation, and drops over the Grand Falls of the Little Colorado shortly after. Below Grand Falls, the river flows through a short but rugged canyon for about . Emerging into the desert again, the Little Colorado skirts the eastern edge of Wupakti National Monument and passes the town of Cameron, where it is bridged by U.S. Highway 89. From Cameron, the Little Colorado River carves an extremely steep and narrow gorge into the Colorado Plateau, eventually achieving a maximum depth of about . The depth of the canyon is such that groundwater is forced to the surface, forming numerous springs that restore a perennial river flow. It joins Colorado deep inside the Grand Canyon, miles from any major settlement.〔 The confluence marks the end of the Marble Canyon segment of the Grand Canyon and the beginning of Upper Granite Gorge.〔http://fire.biol.wwu.edu/trent/alles/GrandCanyon.pdf〕 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「Little Colorado River」の詳細全文を読む スポンサード リンク
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