It's time for fly fishermen to break out their grasshopper fly patterns and head to the rivers.

Hopper flies are taking trout on rivers like the Bighorn, Boulder and Stillwater. Flows remain higher than normal for this time of year -- so watch yourself when wading -- but they're coming down and clearing and offering good fishing.

The weeks of late summer are typically a good time to use terrestrial patterns like hoppers with good dry fly fishing on through the fall.

Reservoir fish are heading deeper across Montana with much of the walleye action down at 18 to 20 feet as fish escape the hot summer sun and rising temperatures.

Here's this week's Billings Gazette Fishing Report:

Canyon Ferry Reservoir: Rainbows have gone into deeper water, and fishing has picked up a little. Rainbows are being caught around Goose Bay and between Confederate and Duck Creek while trolling cowbells and wedding rings with a worm. Walleye are being caught throughout the reservoir and the best action has been in the early morning and evening. Bay points on the North end, Confederate, Duck Creek Bay and Ponds 2 & 3 have shown best results. -- FWP, Helena.

Gallatin River: The river is in great shape and both the canyon and valley are fishing equally well. Terrestrials are about a week away. It's dry fly time up in the canyon with PMDs cast near the banks doing well and some caddis, yellow sallies and golden stoneflies on the water. -- Montana Troutfitters, Bozeman.

Hauser Reservoir: Rainbow fishing has been slow, but some are being caught while trolling cowbells. Walleye action has been good around Black Sandy; however, most fish are small. The best bet has been while using bottom bouncers and worms in 15 feet of water. -- FWP, Helena.

Holter Reservoir: Rainbow fishing is good while trolling cowbells tipped with a crawler around Split Rock and just above the dam. The rainbows are being caught in the early morning in 25 to 30 feet of water. Walleye fishing is very good with most action happening around Cottonwood Creek, Split Rock and shallow bays. The best bet is using chartreuse jigs or bottom bouncers in 12 to 15 feet of water in the late evenings. -- FWP, Helena.

Madison River: PMDs, Fish are keying on yellow caddis, flying black ants, yellow sallies and golden stones in the morning and evenings. Around mid-day, switching to nymphs is the way to go. -- Montana Troutfitters, Bozeman.

Missouri River, Below Holter: Ants, Hoppers and Drakes are starting to come off. The dry fly action is phenomenal with caddis and PMDs going off up top and sallies and drakes down lower. Your typical tailwater nymph rigs such as pheasant tails, scuds and lightning bugs will bet your best bet to pick up fish if there are no heads up top feeding on dries. -- Montana Troutfitters, Bozeman.

Yellowstone River, Livingston: Nymphing is the best way to go unless streamer fishing is your thing. The whitefish bite is on for sure, so get the cooler and smoker and have a whitefish smokeout after a good day of fishing. Stay up higher for dry fly fishing; stay mid to lower for streamer action. -- Montana Troutfitters, Bozeman.