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353:), causing them to drop their moisture in the form of rain or snowfall onto the Cascades. As a result, the west side of the North Cascades experiences high precipitation, especially during the winter months in the form of snowfall. During winter months, weather is usually cloudy, but, due to high pressure systems over the Pacific Ocean that intensify during summer months, there is often little or no cloud cover during the summer Because of
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225:. The South Fork Nooksack River flows around the eastern end of Twin Sisters Mountain. Other streams that drain Twin Sisters Mountain include Skookum Creek, Sister Creek, Green Creek, and Howard Creek. All the streams eventually end up in the Nooksack River.
209:. Of its two main peaks, South Twin is higher, with a summit elevation above 7,004 feet (2,135 m). The summit of North Twin is above 6,644 feet (2,025 m). There are several glaciers on the northeast slopes of Twin Sisters Mountain.
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era. The reddish color of the mountain range may be due to the oxidation of iron and magnesium in the dunite that is exposed to chemical
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minerals are thought to have formed during later stages of the uplift where water could penetrate through fault fractures and initiate
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221:. Twin Sisters Mountain as a whole is located southwest of Mount Baker, separated from the volcano by the Middle Fork of the
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297:. These minerals are commonly associated with ultramafic rocks that crystallize below the Earth's crust within the
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Beckey, Fred W. Cascade Alpine Guide, Climbing and High Routes. Seattle, WA: Mountaineers Books, 2008.
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245:. The Twin Sisters Range is a massive slab of relatively dense rock that was
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527:"Generalized Geological Map of the Mount Baker 1:100,000 Quadrangle"
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rich rocks that contain, along with olivine, significant amounts of
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257:. The magnesium and iron rich rock was forced upwards from the
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summit elevation of North Twin between 6644 ft. and 6684 ft.
349:, they are forced upward by the peaks of the Cascade Range (
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summit elevation of South Twin between 7004 ft. and 7044 ft
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Twin
Sisters Mountain is composed of relatively unaltered
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16:Multi-peak mountain in Washington State, U.S.
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33:As seen from southern flank of Mount Baker
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697:United States Department of the Interior
675:United States Department of the Interior
653:United States Department of the Interior
553:"Emplacement of the Twin Sisters Dunite"
453:United States Department of the Interior
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719:Mountains of Whatcom County, Washington
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281:of the Twin Sisters dunite consists of
217:Both of the summits are located within
189:, "red mountain"), commonly called the
729:Mount Baker-Snoqualmie National Forest
509:Washington Road & Recreation Atlas
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724:North Cascades of Washington (state)
688:Geographic Names Information System
666:Geographic Names Information System
644:Geographic Names Information System
444:Geographic Names Information System
341:, and travel northeast toward the
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325:Twin Sisters are located in the
261:collision between the Bell Pass
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714:Mountains of Washington (state)
693:United States Geological Survey
671:United States Geological Survey
649:United States Geological Survey
467:"Cultural Resources Department"
449:United States Geological Survey
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592:"Rocks of the Western Domain"
531:North Cascades geological map
205:, it lies just southwest of
59:3,520 ft (1,070 m)
560:American Journal of Science
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253:activity in the form of a
87:48.7045599°N 121.9873731°W
596:USGS Geology in the Parks
390:Peakbagger.com lists the
377:Peakbagger.com lists the
345:. As fronts approach the
265:and the Chilliwack River
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551:Ragan, Donal M. (1963).
491:"North Twin, Washington"
421:"South Twin, Washington"
329:climate zone of western
321:Twin Sisters west aspect
92:48.7045599; -121.9873731
639:"Twin Sisters Mountain"
193:, is a mountain in the
598:. USGS. Archived from
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219:Mount Baker Wilderness
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49:7,000+ feet (2,130+ m)
572:10.2475/ajs.261.6.549
471:NookSack Indian Tribe
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179:Twin Sisters Mountain
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144:Twin Sisters Mountain
22:Twin Sisters Mountain
241:rock that is mostly
187:Kwetl’kwítl’ Smánit
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174:Twin Sisters range
39:Highest point
343:Cascade Mountains
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683:"North Twin"
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661:"South Twin"
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604:. Retrieved
600:the original
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439:"South Twin"
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307:metamorphism
295:serpentinite
251:thrust fault
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191:Twin Sisters
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124:Parent range
269:during the
249:from major
207:Mount Baker
90: /
78:121°59′15″W
65:Coordinates
708:Categories
606:2007-07-16
577:2013-10-09
537:2007-07-16
476:2013-09-16
402:References
275:weathering
239:ultramafic
199:Washington
195:U.S. state
75:48°42′16″N
55:Prominence
359:avalanche
283:Enstatite
279:Petrology
213:Geography
103:Geography
45:Elevation
361:danger.
287:chromite
271:Mesozoic
259:tectonic
247:uplifted
183:Nooksack
137:Topo map
108:Location
515:. 2000.
392:NAVD 88
379:NAVD 88
333:. Most
313:Climate
267:terrane
263:Mélange
243:olivine
229:Geology
160:Igneous
149:Geology
533:. USGS
301:. The
293:, and
235:dunite
163:dunite
556:(PDF)
365:Notes
255:nappe
237:, an
142:USGS
568:doi
564:261
197:of
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181:(
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
