Big Muddy Creek (Missouri River tributary) Big Muddy Creek (Missouri River tributary) Big Muddy Creek is a tributary of the Missouri River, approximately 191 mi (307 km) long, in the Canadian province of Saskatchewan and the U.S. state of Montana. It flows through the Big Muddy Badlands. It rises in southern Saskatchewan at Willow Bunch Lake, on the plains north of the international border and approximately 20 mi (32 km) northwest of Big Beaver. It flows southeast through the Big Muddy Badlands and through Big Muddy Lake, then south into Sheridan County, Montana, past Redstone, then east, past Plentywood, then south, forming the eastern border of
Big Wood River receives the tributary streams of Warm Springs Creek and Trail Creek. Below Ketchum, it is joined by the East Fork Wood River at Gimlet before passing by the small cities of Hailey and Bellevue. Continuing south, the river enters the Wood River Valley, the northern part of Magic Valley, after which it flows into Magic Reservoir. A tributary stream, Camas Creek, joins the river in Magic Reservoir. Below Magic Dam, the Big Wood River enters Lincoln County, passing by many lava beds and irrigation canals before entering Gooding County. Just west of Gooding, the Big Wood River joins the Little