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18-529: The Denali Fault is located in the southern half of Alaska in the Alaska Range . It is more than 1,250 miles long, arcing through southern Alaska, southwestern Yukon , and back into southeastern Alaska. The steep north face of Denali , known as the Wickersham Wall, rises 15,000 feet from its base, and is a result of relatively recent vertical movement along the fault. Alaska's network of faults

36-718: Is a relatively narrow, 600-mile-long (950 km) mountain range in the southcentral region of the U.S. state of Alaska , from Lake Clark at its southwest end to the White River in Canada 's Yukon Territory in the southeast. Denali , the highest mountain in North America , is in the Alaska Range. The range is part of the American Cordillera . The Alaska Range is one of the higher ranges in

54-680: Is a result of tectonic activity; the Pacific plate is actively subducting (sliding under) the North American plate, and the Denali Fault is located on the boundary between the two plates. Along the Denali Fault, lateral and vertical offset movement is taking place at a rate of approximately 13 mm/yr. Around 300 to 400 kilometers of displacement has occurred since the Cretaceous, and about 25% of that displacement has occurred since

72-756: Is part of the Pacific Ring of Fire , and the Denali Fault that runs along its southern edge is responsible for many major earthquakes . Mount Spurr is a stratovolcano located at the northeastern end of the Aleutian Volcanic Arc which has two vents, the summit and nearby Crater Peak. Parts of the Alaska Range are protected within Wrangell-St. Elias National Park and Preserve , Denali National Park and Preserve , and Lake Clark National Park and Preserve . Several highways cross through

90-755: The Alaska Range , the river flows north to meet the larger river near Big Delta . It is older than the Alaska Range , being formed before their uplift 30 million years ago. In 1980, 62 miles (100 km) of waterways in the Delta River basin, including all of the Tangle Lakes and the main stem to within 0.5 miles (0.8 km) of Black Rapids became part of the National Wild and Scenic Rivers System . Of this, 20 miles (32 km) are designated "wild", 24 miles (39 km) "scenic", and 18 miles (29 km) "recreational". Easily accessible from

108-645: The Tanana River via Miles Pass. He noted that it would be possible to build a road from Prince William Sound to the Yukon River . Six years later, Frederick Schwatka and Charles W. Hayes crossed the extreme eastern end of the range via the White River and into the Copper River basin through Skolai Pass in what is now called Saint Elias Mountains . In 1898, W. C. Mendenhall and E. F. Glenn traversed Isabel Pass and were within 15-20 miles of

126-504: The Totschunda Fault . The resulting surface rupture was approximately 336 kilometers (209 miles) long, and it cut through streams, divided forests, opened chasms in roads, and even generated fault traces visible across several glaciers. Because the earthquake released most of its energy on the sparsely populated eastern end of the fault, Alaska's major cities were spared serious damage. Alaska Range The Alaska Range

144-677: The "Chigmit Mountains" and the northeastern part the "Beaver Mountains". However, the Chigmit Mountains are now considered part of the Aleutian Range . Starting in the mid 1880s to early 1900s, early non-native explorers traversed various sections of the Alaska Range. The first recorded expedition was in the Eastern Alaska Range led by H. T. Allen in 1885. His team went from Suslota Lake to Tetlin Lake and unto

162-679: The Miocene. According to tree ring studies, a magnitude 7.2 to 7.4 earthquake happened along the fault in 1912. It was the main fault along which the 2002 Denali earthquake occurred, which was measured as a magnitude of 7.9 M w . During the afternoon of November 3, 2002, the water in Seattle's Lake Union suddenly began sloshing hard enough to knock houseboats off their moorings. Water in pools, ponds, and bayous as far away as Texas and Louisiana splashed for nearly half an hour. The earthquake began at 1:12 p.m. Alaska local time, and

180-634: The Tanana River before turning around. Separately, that same year, Robert Muldrow and George Homans Eldridge crossed Broad Pass then Windy Pass into the Nenana River valley. Delta River The Delta River is an 80-mile (130 km) tributary of the Tanana River in the U.S. state of Alaska . Its name in the Ahtna language is Saas Na’  . Fed by the Tangle Lakes of

198-657: The boat launch at the Tangle Lakes campground near the Denali Highway and at many points downstream along the Richardson Highway , the river can be floated in sections that vary in difficulty from Class I (easy) to Class V (extremely difficult) on the International Scale of River Difficulty and may require portages . The upstream stretches include four lakes and their Class II (medium) connecting channels. About 2 miles (3 km) downstream of

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216-494: The difficulty is Class III rising to Class IV (very difficult) or V, followed by 30 miles (48 km) of Class III and then 18 miles (29 km) of Class I. Author Karen Jettmar warns of dangers including "sweepers, canoe fragments wrapped around rocks, bears, cold and wet weather, and high winds". She says that "only experts should attempt to run Black Rapids (Class IV–V) below Mile 229 on Richardson Highway." The Tangle Lakes complex, 24 miles (39 km) long, that feeds

234-579: The harshest weather in the world. The heavy snowfall also contributes to a number of large glaciers , including the Cantwell , Castner , Black Rapids, Susitna , Yanert , Muldrow , Eldridge , Ruth , Tokositna , and Kahiltna Glaciers. Four major rivers cross the Alaska Range, including the Delta and Nenana Rivers in the center of the range and the Nabesna and Chisana Rivers to the east. The range

252-456: The last lake, the river enters a canyon and flows over unrunnable waterfalls. A 0.5-mile (1 km) portage leads to a 2-mile (3 km) stretch of Class III (difficult) rapids. Below the Class III rapids, the river continues through 29 miles (47 km) of Class I and II water before entering a 20-mile (32 km) stretch between Ann Creek and One Mile Creek known as Black Rapids . Here

270-595: The passes of the range: the George Parks Highway from Anchorage to Fairbanks via Windy Pass, the Richardson Highway from Valdez to Fairbanks via Isabel Pass , and the Tok Cut-Off from Gulkana Junction to Tok, Alaska via Mentasta Pass . The Alaska Pipeline parallels the Richardson Highway . A part of the Alaska Highway is situated on the northern slopes of the eastern section of

288-547: The range. The name "Alaskan Range" appears to have been first applied to these mountains in 1869 by naturalist W. H. Dall . The name eventually became "Alaska Range" through local use. In 1849 Constantin Grewingk  [ de ] applied the name "Tschigmit" to this mountain range. A map made by the United States General Land Office in 1869 calls the southwestern part of the Alaska Range

306-787: The world after the Himalayas and the Andes . The range forms a generally east–west arc with its northernmost part in the center, and from there trending southwest towards the Alaska Peninsula and the Aleutian Islands , and trending southeast into British Columbia and the Pacific Coast Ranges . The mountains act as a high barrier to the flow of moist air from the Gulf of Alaska northwards, and thus have some of

324-533: Was centered approximately 135 kilometers (84 miles) south of Fairbanks and 283 kilometers (176 miles) north of Anchorage . Shaking at the epicenter lasted approximately 1.5 to 2 minutes, but in Fairbanks the duration of the earthquake was over 3 minutes. Originating on the previously unknown Susitna Glacier Fault, the earthquake shot eastward along the well-known Denali Fault at a speed of over 11,265 kilometers (7,000 miles) per hour before branching southeast onto

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