Area ranching history Local rancher and historian, Jonita Sommers talks to the students about the history of the Green River cattle drift, which has been taking place for more than 100 years in the Upper Green River Valley. Her family ranch has been a part of the Drift during that time period, and still is today. Jonita wrote a book about the Green River Drift. Efforts are underway by the Wyoming State Historic Preservation Office to designate the Drift path on the National Register of Historic Places.