Idaho Rivers


What to Expect in August

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

In general, August presents tough fishing conditions: the water is warm, the sun is bright, and trout have seen hundreds of anglers and thousands of fake insects. Further, most of the big, intense hatches are over, leaving well-fed trout that are not as strongly motivated as the anglers who pursue them.

Still, if you remember a few basic guidelines and adjust your tactics, August can offer excellent fishing. First and foremost, concentrate your fishing during the most productive hours. Early morning is often the best time; this when you are most likely to experience a trico hatch or spinner fall. Evenings can be good as caddis activity peaks, but hot days will result in shorter--and more intense--fishing in the evening. During the heat of the day trout will be more reluctant to come to the surface. At that time of day, hoppers may entice them, and nymphs can be productive; so the best strategy is to combine the two in a "hopper/dropper" rig

Put that all together and you get the August mantra: "hopper, dropper, trico, caddis." Remember that chant--throwing in an occasional "PMD" and "pink Albert"--and you'll reach September with a smile on your face.

Terrestrials are one of the big events for August.

To put a dropper off your hopper, use a clinch knot to tie a section of tippet to the hopper's hook bend. Tie a small nymph or caddis pupa imitation to the other end. During the day, a24-30 inch dropper is usually appropriate, but sometimes a longer leader is needed. A 12-18 inch dropper can be used during the evening hours when trout are more willing to come near the surface.

Tricos can vary from size18 to size 24, so snag a natural insect and make sure your imitation matches the real bug. The three Ps--presentation, persistence, patience--will aid in success.

There are hundreds of species of caddis in the West, and many of them are on the water at the same time. Because trout see many sizes and colors of caddis, you seldom have to match this insect with the same precision that mayflies require. Match the size and general color of the majority of caddis on the water and you'll probably do well. The most important thing is to match your fly choice to the type of water you're fishing. A bushy Elk Hair Caddis will work well on rough, riffly water. But the same fly can fail miserably on flat runs and spring creeks. For softer water, you'll need a fly with less hackle and a lower profile, such as a CDC Caddis or Parachute Caddis. In a pinch, you can trim the hackle from the bottom of an Elk Hair Caddis; this can increase the fly's effectiveness on certain types of water.

The Casanova Caddis has become a favorite of mine. The deer hair dubbing makes a realistic body, although it takes some practice to use that material correctly. Also, the Raffia wing can be in shreds after6-8 trout.

Pale morning duns may be present on some rivers early in the month, but they are on the way out and will seldom be seen after the first week of August.

Pink alberts are a midday hatch on some rivers this month. The body is a creamy pink color. You can match it by mixing pink dubbing with cream dubbing. A Sparkle Dun or Light Cahill style of dry fly is adequate.


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