Rising along the Continental Divide in southwestern Montana and northwestern Wyoming, the Missouri River exits the Rocky Mountains at Great Falls and then flows eastward across the Northern Plains. In eastern South Dakota it turns to the south, forming the common borders of Nebraska, Iowa, Kansas and Missouri; at Kansas City, it flows eastward once again, dipping through Missouri and merging with the Mississippi just north of St. Louis.
Before modern man dammed and channelized it, the Missouri was a wide, braided, meandering river as it crossed the vast, semiarid Northern Plains. Numerous oxbows and extensive wetlands bordered its channel, offering irresistable reststops for migrant waterfowl. As the only major river system in that part of the Continent, the Missouri became a natural highway for these migrants, guiding them from their arctic and prairie breeding grounds to wintering areas along the lower Mississippi Valley and Gulf Coast.
Though man has altered its flow and drained most of its wetlands, the Missouri remains the primary route for migrant waterfowl in the Central Flyway of North America. Numerous wildlife refuges line its corridor and November is one of the best months to visit these preserves. The DeSoto National Wildlife Refuge, on the Iowa-Nebraska line, and Squaw Creek National Wildlife Refuge, in northwest Missouri, are two of the best.
