Idaho Rivers


What to Expect in July

Note: This What-To-Expect is from Westfly's Legacy pages and may not accurately reflect the current fishing at this venue

Pale morning duns are the big news on many Idaho rivers this month. These ubiquitous little insects can create intense hatches that make trout feed aggressively on the surface--and make anglers' hearts thump loudly. It's not a difficult hatch if you have the right flies, such as size 18 Sparkle Duns, PMD Cripples, Parachute PMDs, or No Hackles. The quieter and clearer the water, the less hackle your fly should have. A downstream presentation is often needed on glassy, clear water or spring creeks.

Yellow sallies may be either yellow stoneflies or little green stoneflies, depending on where you are. Trout don't have names for them--Latin or English--and if you match the size and color of the natural you'll do well. The afternoon and evening hours are the best times to fish an adult pattern.

Caddis are the other big news in July. Most of the action is in the afternoon and evening. Often, dry fly fishing just gets better and better as you get closer to dark. Many anglers go home too early and miss the best fishing of the day. The important thing to remember about caddis season is: "close is good enough." There are so many caddis species and so much variation in size and color, that you seldom need the perfect imitation like you sometimes do for mayflies. Choose a size and color that comes close to the prevailing insects. Next, choose a pattern based on the type of water: a well-hackled, high-floating fly for fast, rough water; a flush-floating fly with less (or no) hackle for slow water with a smooth surface. Above all, a good presentation is essential

Hoppers will become important near the end of the month. Beetles and ants are important all month.

Tricos are another hatch that takes center stage near the end of July.

Some Idaho rivers will have late or remnant hatches of golden stoneflies or even salmonflies this month.

Hot weather can push the action into the morning and evening hours. It can be difficult to get trout to come to the surface during hot afternoons, but you can still pick up some fish if you use your dry fly as an indicator and tie24-30 inches of leader to the hook bend; attach a size 12-16 Copper John, Pheasant Tail, or Prince on the end of the dropper. Shorten the dropper length for evening fishing. If the water temperature is 72 degrees or over, DON'T FISH; it's too hard on the trout.


Other Months

What to expect in 


Other Rivers or Lakes