Flathead Lake is the largest natural freshwater lake west of the Mississippi. Paddling to Wildhorse Island is scenic and well worth the visit. This area is popular for fishing and the opportunity to see wild horses, big-horn sheep, deer and many species of birds. Wild Horse Island is for day use only but Cedar Island which is just north offers good camping. Best time to travel is early morning because of the winds and waves that can be nasty in the afternoon.services and launch ramps. Fishing is popular and towards the south end are a few beautiful islands to paddle to.