Float tube fly fishing on some of the rainbow stocked lakes on the Blackfoot Reservation can be spectacular. You have to pay extra for a tribal permit but the fishing is usually worth it. If the wind's not blowing too hard. Early morning or just at dusk there's usually not much blowing. Scenery there is also quite spectacular. No guides needed. Duck Lake and Mission Lake are the two big ones. Duck Lake may be getting quite weedy by now. You can also hike in to the Upper Two Medicine just off the Reservation and get some fine river fishing although the water level may be a bit low this late.