|
Lake Shannon is a long, narrow reservoir on the Baker River in Skagit County in the U.S. state of Washington. Formed in the 1920s by the construction of an arch dam just above the river's mouth, the lake is approximately long and averages wide at full extent. Lake Shannon is part of a cascade of two reservoirs, the Baker River Hydroelectric Project, built on the lower half of the Baker River by Puget Sound Energy for generating hydroelectricity. The reservoir is located just outside the western boundary of North Cascades National Park and just north of Concrete. Historically Lake Shannon did not exist and Baker Lake was smaller, and the Baker River area was used primarily for fur trapping, logging, and concrete making. The formation of the lake led to problems with migrating salmon in the Baker River, which would often exceed 20,000 annually. A fish passage system was begun in the 1950s and completed in 1959 after the construction of Upper Baker Dam, the uppermost Baker River reservoir. The lake has an abundant population of kokanee salmon, the by-product of salmon spawning in lake tributaries. Fishing, boating and water skiing are popular activities on the lake, which partially lies in the Mount Baker National Forest. ==Description== The Baker River flows southeast and south for about to meet the Skagit River at Concrete. Less than 1 mile (1.6 km) above its mouth, a arch dam, the Lower Baker Dam, straddles an extremely tight and narrow gorge to form Lake Shannon, a lake. The lake occupies a cleft in the Baker River Valley between a prominent river terrace to the west and a less obvious one on the east. While the west slope directly above the lake is dissected with many canyons, the east slope is smaller and smoother. The lake is surrounded by prominent forested mountains, but the surrounding terrain is not as steep and rugged as the upper watershed. The reservoir is widest in the lower half and especially in a stretch about upstream of the dam. Near the middle, the lake narrows dramatically as it squeezes between the west shore and a narrow promontory that juts out into the valley. The upper half of the lake is very narrow, and the far upper end protrudes into the Mount Baker National Forest. Just above the north end of the lake, the Upper Baker Dam blocks the Baker River once again to form an expanded Baker Lake. The dominant geographical feature in the area is Mount Baker, which rises a few miles to the northwest of Lake Shannon. Mount Shuksan, a slightly smaller peak, rises further to the north-northeast. Aside from the Baker River, some major streams that feed the lake are Thunder Creek (which meets the lake near the promontory that nearly severs it in half) and Sulphur Creek, which flows directly into the lake during high water.〔 The Baker River Road runs in a northerly direction along the east side of Lake Shannon into North Cascades National Park, while the North Cascades Highway crosses the Baker River just below Lake Shannon. Although most of the inflow to Lake Shannon is from releases from Upper Baker Dam, it also receives inflow from of adjacent watershed.〔 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「Lake Shannon」の詳細全文を読む スポンサード リンク
|