Big Muddy River The Big Muddy was not covered by the Wisconsin Glacier, about 70,000 to 10,000 years before present. However, during the melting of that glacier, the level of the Mississippi River was much higher. Water backed up into the Big Muddy Basin, forming a lake much like the artificial Rend Lake but covering a larger area. The ancient lake silted in, forming a flat bottom. After the melting of the Wisconsinan glacier, the level of the Mississippi dropped, allowing the lake to drain. A new channel formed within the old lake bed. This channel meandered in the flat bottom of the
Greybull River Greybull River The Greybull River is a tributary of the Big Horn River, approximately long in northern Wyoming in the United States. The river was reportedly named for a white buffalo that had been seen on its banks. Native Americans consider the appearance of a white buffalo a powerful omen. The river rises near Francs Peak in the Absaroka Mountains in the southwest corner of the Big Horn Basin. It joins with the Wood River and leaves the mountains near the town of Meeteetse, continuing through the southern parts of Park County and Big Horn County before flowing into the