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 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.
9-573: 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 the boat launch at
18-414: A main stem or mainstem (also known as a trunk ) is "the primary downstream segment of a river , as contrasted to its tributaries ". The mainstem extends all the way from one specific headwater to the outlet of the river, although there are multiple ways to determine which headwater (or first-order tributary) is the source of the mainstem. Water enters the mainstem from the river's drainage basin ,
27-626: A Strahler number of 10, the highest in the nation. Eight rivers, including the Columbia River , reach 9. Streams with no tributaries, assigned the Strahler number 1, are most common. More than 1.5 million of these small streams, with average drainage basins of only 1 square mile (2.6 km ), have been identified in the United States alone. Outside of the United States, the Amazon River reaches
36-588: A second-order stream; when two second-order streams meet, they form a third-order stream, and so on. In the Horton system, the entire mainstem of a drainage basin was assigned the highest number in that basin. However, in the Strahler system, adopted in 1957, only that part of the mainstem below the tributary of the next highest rank gets the highest number. In the United States, the Mississippi River mainstem achieves
45-477: 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
54-489: The Delta River has "some of the best road-accessible grayling fishing in Interior Alaska". In the deeper lakes of the system, lake trout are fairly abundant. Lakes and streams that are away from the highway and accessible only by canoe or trail are the least heavily fished. Arctic grayling fishing is also considered excellent on the upper river down to its confluence with Eureka Creek. Main stem In hydrology ,
63-614: 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
72-462: The land area through which the mainstem and its tributaries flow. A drainage basin may also be referred to as a watershed or catchment . Hydrological classification systems assign numbers to tributaries and mainstems within a drainage basin. In the Strahler number , a modification of a system devised by Robert E. Horton in 1945, channels with no tributaries are called "first-order" streams. When two first-order streams meet, they are said to form
81-465: 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 the difficulty
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