From the benchThe frost won't lift until 10 AM, so don't rush the morning — use that time to scout rising fish from the bank rather than wading and spooking them. Once the sun hits the water and temps climb toward 50°F, the BWO hatch will fire hard between 11 AM and 2 PM in the meadow sections near Fountain Flat. Position yourself downstream of rising fish, make a reach cast upstream, and keep your drift drag-free for at least 6–8 feet — these Firehole browns have seen every fly in the book and will refuse anything with the slightest skate. Switch to a nymph fished in the top 12 inches if you see fish bulging but not fully breaking the surface.