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〕 }} Diamond Lake is a natural body of water in the southern part of the U.S. state of Oregon. It lies near the junction of Oregon Route 138 and Oregon Route 230 in the Umpqua National Forest in Douglas County. It is located between Mount Bailey to the west and Mount Thielsen to the east; it is just north of Crater Lake National Park. The outlet of the lake is at its north end. From there, water flows via Lake Creek into the North Umpqua River and ultimately to the Pacific Ocean.〔U.S. Geological Survey topographic maps〕 Diamond Lake was named for John Diamond, for whom Diamond Peak is also named. He saw the lake in 1852 while on the summit of Diamond Peak. Diamond was a pioneer settler of Coburg, Oregon, and part of a party opening a road between the Middle Fork Willamette River and Idaho as an immigration route. An adjacent post office named Diamond Lake, Oregon, was established in 1925 and ran until 1956, when it was changed to a summer-only office.〔 ==Fish== Although rainbow trout are not native to Diamond Lake because the lake lacks the required spawning habitat, large populations of aquatic insects make it ideal for fish.〔 After treating the lake to remove rough fish in 1954, the Oregon Department of Fish and Wildlife (ODFW) stocked the lake with a Canadian strain of rainbow trout and later added local strains in about 1970.〔 Stocked trout grew rapidly in the lake, and before other species began competing successfully with trout, anglers caught rainbows regularly, and the average catch weighed more than . However, in 1992 a non-native species, tui chub, was detected in the lake. These fish, illegally introduced to the lake, quickly multiplied and negatively affected the sport fishery. The water became murky, the insect population dropped dramatically, and the trout population declined.〔 To eliminate the unwanted fish, the ODFW poisoned Diamond Lake with rotenone in 2006. This killed 95 million tui chub, and the lake became free of them. By 2007 dramatic improvements were noted in water clarity, insect populations, and the trout catch. The ODFW has captured golden shiners, another invasive species of bait fish illegally introduced to the lake. Although shiners are less successful than tui chubs at multiplying in Diamond Lake, the ODFW works to remove them and to discourage more from being added.〔 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「Diamond Lake (Oregon)」の詳細全文を読む スポンサード リンク
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