The Curlew Valley is a 23-mile long valley located on the northern edge of the Great Salt Lake in Box Elder County in northern Utah and extending north into Oneida County in southern Idaho. Within northeast Box Elder County, the southwest of the valley abuts the Locomotive Springs Wildlife Management Area and an extensive salt flat on the edge of the Grea…The Curlew Valley is a 23-mile long valley located on the northern edge of the Great Salt Lake in Box Elder County in northern Utah and extending north into Oneida County in southern Idaho. Within northeast Box Elder County, the southwest of the valley abuts the Locomotive Springs Wildlife Management Area and an extensive salt flat on the edge of the Great Salt Lake.