The Iowa Great Lakes The main attractions of the Okoboji area are the glacier-carved lakes. The Iowa Great Lakes include Iowa's largest natural lake, Spirit Lake and five interconnected lakes: West Okoboji, East Okoboji, Upper Gar, Lower Gar and Minnewashta. The spring-fed West Okoboji Lake is a beautiful shade of blue and 134' deep. It is the centerpiece of the five chain lakes, and the surrounding communities provide the backdrop for Okoboji's year around playground.