Middle Fork Koyukuk River

Middle Fork Koyukuk River
Location of the mouth of the Middle Fork Koyukuk River in Alaska
Location
Country	United States
State	Alaska
Census Area	Yukon–Koyukuk
Physical characteristics
Source	Confluence of Bettles and Dietrich rivers
• location	near Wiseman, Brooks Range
• coordinates	67°38′26″N 149°44′29″W / 67.64056°N 149.74139°W / 67.64056; -149.74139[2]
• elevation	1,419 ft (433 m)[3]
Mouth	Koyukuk River[1]
• coordinates	67°02′30″N 151°04′00″W / 67.04167°N 151.06667°W / 67.04167; -151.06667[1]
• elevation	724 ft (221 m)[3]
Length	62 mi (100 km)[1]

The Middle Fork Koyukuk River is a 62-mile (100 km) tributary of the Koyukuk River in the U.S. state of Alaska.^[1] Formed by the confluence of the Bettles and Dietrich rivers near Wiseman on the southern flank of the Brooks Range, the Middle Fork flows generally southwest to its confluence with the North Fork Koyukuk River, with which it forms the main stem of the Koyukuk.^[1][4]

From its starting point slightly north of Sukakpak Mountain, the river flows generally south or southwest in its upper reaches. The Dalton Highway and the TransAlaska Pipeline run roughly parallel to the river between its source and a point between Twelvemile Mountain, on the river's right, and Cathedral Mountain, on the left, south of Coldfoot. Further south, at Tramway Bar, the river turns generally west to its confluence with the North Fork Koyukuk River.^[5]