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
Course of the Colorado River colorful and intricately sculpted rock formations. The Escalante River, a desert stream which runs through the sinuous slot canyons of Grand Staircase-Escalante National Monument, joins about two-thirds of the way down Lake Powell. The San Juan River, which carries runoff from the southern slopes of the San Juan Mountains and the Four Corners region in Colorado and New Mexico, joins several miles further downstream; it forms an arm of the lake nearly long. Although the San Juan contributes only about one-tenth of the Colorado River flow, it is extremely muddy, contributing as much as 40 percent of the total sediment