Idaho Report/Forecast for August

Idaho Rivers in General

What to Expect in August:

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.

If it is a drought year, August presents the additional challenge of warm water and--sometimes--shortened fishing hours or even closures. It is not unusual for the fishing hours on some rivers to be curtailed to midnight to 2:00 p.m.

Terrestrials are one of the big events for August. Western Hatches: Terrestrials by Rick Hafele and Dave Hughes has some good thoughts on fishing terrestrials. While hoppers get most of the attention, beetles and ants are usually more important food-forms for trout. See Jeff Morgan's articles on these overlooked terrestrials: Tying Better Ant Patterns and Meeting the Late Summer Challenge.

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, a 24-30 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.

For tips on fishing the trico hatch/spinner fall, see Tricos Without Tears. Tricos can vary from size 18 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 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 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 profoundly 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 after 6-8 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.

Idaho Lakes in General

What to Expect in August:

With few exceptions, August is not a good option for lowland reservoirs. The high lakes are the place to be.

Big Lost River

What to Expect in August:

Look for flows under 300 cfs. Something around 200 cfs is even better.

If there is a trico hatch, expect it around 9:30 a.m. or 10:00 a.m. The hatch/spinner fall can last until 1:00 p.m. There may be a repeat performance in the evening beginning around 5:00 or 6:00 and lasting as long as there's light. Size 22-24 flies are needed to match the tricos. A Parachute Trico (like a Parachute Baetis, but black body), Bubble Parachute, or No Hackle works well for the dun stage. A Polywing Spinner or CDC Biot Spinner can work for the spinner stage. Sunny days will improve the trico hatch. See Tricos Without Tears for tips on fishing the trico hatch.

The tailwater below the dam is a good place to cast a size 8-10 Parachute Hopper or similar low-profile imitation during August.

Expect evening caddis hatches. Size 18-20 patterns are needed for the caddis. A few yellow sallies will linger until mid-month.

Cranefly imitations, such as the Mackay Special, are a good August option. Higher water works best for this event: the fly is skated across the surface, so a good flow of water is needed.

On the upper river, in the Copper Basin area, you should have good fishing with hopper and ant patterns, caddis imitations, and size 14-16 attractors such as yellow or red Humpies, and big outrageous flies such as a Turcks Tarantula or Parachute Madam X. A Royal Wulff or Royal Trude is always productive up here. You can also entice trout with a standard beadhead nymph, such as a Prince, Pheasant Tail, Copper John, or Brassie. You can team your nymph with another large nymph and dead drift the rig near the bottom, or use it in combination with an attractor dry fly or hopper.

See the Rivers in General section for more tips on August fly fishing.

For more on August tactics and flies, see the Rivers in General report. See the Big Lost River report for current conditions, hatches, guides, and other information.

Big Wood River

What to Expect in August:

Pink alberts can be expected at midday. A size 16 pink Parachute Hares Ear, Sparkle Dun, or Light Cahill imitates this bug. "Pink" doesn't mean shocking or little-old-lady pink; just blend some pink dubbing with cream dubbing and you'll have the right color.

Tricos should be on the river later in the month. Use size 20-22 black Sprout Midges, Sparkle Duns, or similar flies for the dun stage.

Caddis will be active in the evenings. Size 16-18 patterns with olive or tan bodies, and size 18 with black body and black wing will match most caddis that you'll come across in August.

The Big Wood also offers hopper fishing in August. If you see good-looking water, odds are it holds a few trout that are receptive to a hopper imitation, such as a Parachute Hopper, Whitlock Hopper, or Turcks Tarantula.

If your topwater flies are being ignored, drift a Prince, Copper John, CDC Bubble Brassie, or other nymph down on the bottom.

Most of the Wood's trout are rainbows are in the 12-16 inch range, and the best fishing is between North Fork and Hailey. There's not much point in fishing below Hailey.

See the Rivers in General section for more tips on August fly fishing.

For more on August tactics and flies, see the Rivers in General report. See the Big Wood River report for current conditions, hatches, guides, and other information.

Boise River, South Fork

What to Expect in August:

Expect high flows; this is the irrigation season.

Golden stonefly adults are still around, so be prepared for them in early August. Pink alberts are an important hatch here during August. Typically, this much-anticipated event goes from 1:00 p.m. to 4:00 p.m. or into the evening. Match this mayfly with a size 16 pinkish-bodied Parachute Hares Ear, Light Cahill, or Sparkle Dun.

If the weather is too hot and bright, trout might be reluctant to come to the surface, regardless of what's happening. If you get no surface action, go subsurface with a size 8-10 stonefly nymph, such as a Kaufmanns Stonefly or Rubber Legs; team that big nymph with a size 14-18 Pheasant Tail, Micro Mayfly, or similar small nymph.

Afternoon and evening caddis hatches and egg-laying flights will be common this month, but are rarely intense. Size 12-14 emerger and pupa patterns, such as a Sparkle Pupa or CDC Caddis will work well. Adult imitations such as a Parachute Caddis, X Caddis, or Elk Hair Caddis can also be productive.

Terrestrials are another good August option, so make sure hopper, beetle, and ant patterns are in your fly box.

Expect flav activity in the evenings. Look for them in shady areas after 7:30 p.m.

See the Rivers in General section for more tips on August fly fishing.

For more on August tactics and flies, see the Rivers in General report. See the Boise River, South Fork report for current conditions, hatches, guides, and other information.

Chesterfield Reservoir

What to Expect in August:

If there's any water, trout will be in the deepest parts.

For more on August tactics and flies, see the Lakes in General report. See the Chesterfield Reservoir report for current conditions, hatches, guides, and other information.

Clearwater River

What to Expect in August:

A few A-run steelhead always show up in August in the lower part of the river. These fish move in and out of the Snake River; whichever river is cooler--the Snake or the Clearwater--will have the fish.

For more on August tactics and flies, see the Rivers in General report. See the Clearwater River report for current conditions, hatches, guides, and other information.

Clearwater River, North Fork

What to Expect in August:

The North Fork and its tributaries, such as Kelly Creek, are decent options for August fly anglers. Look for fish in the deeper pools and in quiet water near riffles and rapids. You can also seek fish in tributary creeks with sufficient flow and depth to hold trout. These creeks are often cooler than the main river, so trout move into them in late summer.

Use attractor patterns with yellow, red, or orange bodies, such size 8-10 Clarks Stoneflies, size 12-14 Humpies, Royal Wulffs, Trudes, etc. Fly tiers can vary these standard patterns a bit and come up with something the trout haven't seen a thousand times; your fishing will improve if you do this.

See the Rivers in General section for more tips on August fly fishing.

For more on August tactics and flies, see the Rivers in General report. See the Clearwater River, North Fork report for current conditions, hatches, guides, and other information.

Coeur d'Alene Basin

What to Expect in August:

In the upper basin, the best fishing should be early in the morning and in the evening, which is typical for this time of year. In general, this is not a prime month for the Coeur d'Alene basin; the St. Joe is a better choice.

Look for trout in riffly water and along the banks. The lower river, below Kingston, has springs that add fresh, cool water to the river; look for trout there.

Attractor patterns such as yellow or orange Stimulators or Humpies work well, as do hopper imitations such a Chernobyl Hoppers and Parachute Hoppers. Hopper/dropper combinations, with a size 16-18 Pheasant Tail or Hares Ear on the dropper, are productive at this time of year.

You might find falls of a tiny size 20 flying ant with a black body, so be prepared with appropriate patterns.

In the evenings, look for caddis, especially a size 18 cinnamon-bodied species. Blue-winged olives and pale morning duns may also hatch and get the trout excited.

See the Rivers in General section for more tips on August fly fishing.

For more on August tactics and flies, see the Rivers in General report. See the Coeur d'Alene Basin report for current conditions, hatches, guides, and other information.

Daniels Reservoir

What to Expect in August:

Trout will be in the deep water.

For more on August tactics and flies, see the Lakes in General report. See the Daniels Reservoir report for current conditions, hatches, guides, and other information.

Henrys Fork River

What to Expect in August:

In the Box Canyon, size 6-8 golden stonefly nymphs will work well all month, and adult patterns may still take some trout in the first half of August because trout will often be looking for the old hatch even if a new one has started.

Beadhead Pheasant Tails and Princes in size 14-16 are also a good choice in The Box. Make sure your fly is heavy enough to drift near the bottom in these flows. Small nymphs with a little flash, such as Lightning Bugs, Copper Johns, and CDC Bubble Brassies, can also work well. Double Bunny streamers in olive and gray are also good August choices and can take large trout when the skies are cloudy. Evening caddis and some localized trico activity are other hatches in The Box this month. Wade carefully in the Box.

In the Ranch section, Callibaetis and tricos should be hatching in the slow sections in the morning. Expect more of the same for the rest of the month. Tricos can start as early as 6:30 a.m. and last until 10:00 a.m.; both the dun and spinner stages are important. Trout will take both the dun and nymph stage of the Callibaetis, and may have a definite preference for one over the other; be prepared with flies to match both stages.

Look, too, for hatches of size 18-20 pale morning duns, and maybe some blue-winged olives (cloudy days). PMD hatches can occur throughout the day. Evening spinner falls can concentrate the day's hatch activity, so that is an especially good event to be prepared for.

In the evenings you can also expect caddis hatches. Flavs may be encountered early in the month during the evening hours, but they are mostfly done.

Hoppers, beetles, and ants are other August events. Ants are often overlooked here--at least by anglers; the trout know all about them. See Tying Better Ant Patterns for some good ant patterns. Ants can range from size 14 to size 18; both red and black ants can fall on the water. Beetle imitations will also work well. If ants are on the water, they may be the only thing trout are interested in.

In the seven-mile Railroad Ranch water, you need specialty spring-creek patterns. In my experience, non-locals are best off visiting a local shop such as Trouthunter or Henry's Fork Anglers and ask them what's working best at the time. Then buy your flies there.

From Warm River on downstream, beadhead Pheasant Tails and Princes, as well as Woolly Buggers, can pick up fish. Hopper imitations should also be in your fly box when fishing this section. Expect evening caddis activity. However, you should avoid this section unless an extended cool spell arrives; the water is too warm for safe (to trout) fishing.

See the Rivers in General section for more tips on August fly fishing.

For more on August tactics and flies, see the Rivers in General report. See the Henrys Fork River report for current conditions, hatches, guides, and other information.

Henrys Lake

What to Expect in August:

If you come, carry a variety of nymph and leech patterns, including Krystal Buggers, Halloween Leeches (black and orange Woolly Bugger or leech pattern), Mohair Leeches, California Leeches, and beadhead Mini Leeches.

For more on August tactics and flies, see the Lakes in General report. See the Henrys Lake report for current conditions, hatches, guides, and other information.

Kelly Creek

What to Expect in August:

Kelly Creek is one of the best options for anglers seeking westslope cutthroat in August. Due to the heat, trout will be looking for cooler water with more oxygen. Checkout the deeper pools and quiet water near riffles and rapids. You can also seek fish in tributary creeks with sufficient flow for fish. These creeks are often cooler than the main river, so trout move into them in late summer.

Use attractor patterns with yellow, red, or orange bodies, such as size 8-10 Clarks Stoneflies, size 12-14 Humpies, Royal Wulffs, Trudes, etc. Fly tiers can vary these standard patterns a bit and come up with something the trout haven't seen a thousand times; your fishing will improve if you do this.

See the Rivers in General section for more tips on August fly fishing.

For more on August tactics and flies, see the Rivers in General report. See the Kelly Creek report for current conditions, hatches, guides, and other information.

Lochsa River

What to Expect in August:

The Lochsa is a reasonable option for August, although you'll probably do better in the North Fork Clearwater or its tributaries such as Kelly Creek.

Use attractor patterns with yellow, red, or orange bodies, such size 8-10 Clarks Stoneflies, size 12-14 Humpies, Royal Wulffs, Trudes, etc.

See the Rivers in General section for more tips on August fly fishing.

For more on August tactics and flies, see the Rivers in General report. See the Lochsa River report for current conditions, hatches, guides, and other information.

Mackay Reservoir

What to Expect in August:

Try the willows at the upper end, where the inflow is.

For more on August tactics and flies, see the Lakes in General report. See the Mackay Reservoir report for current conditions, hatches, guides, and other information.

Magic Reservoir

What to Expect in August:

Fishing can be expected to slow down considerably in the August heat.

For more on August tactics and flies, see the Lakes in General report. See the Magic Reservoir report for current conditions, hatches, guides, and other information.

Salmon River, Lower

What to Expect in August:

Steelhead bound for the lower Salmon will not arrive until the weather cools down enough to drop the temperature of the Snake. At this time, most of the steelhead will head for the Clearwater's lower temperatures. Seek your early steelhead in that river instead of the lower Salmon.

For more on August tactics and flies, see the Rivers in General report. See the Salmon River, Lower report for current conditions, hatches, guides, and other information.

Salmon River, Upper

What to Expect in August:

Trout anglers should do well with hoppers and caddis, as well as attractors such as Parachute Adams, as well as yellow or orange Stimulators or Humpies. A size 8 Clarks Stonefly can do very well with these fish, too. A size 4-6 olive or olive and white streamer, such as a Matuka, will also take trout if the water is deep enough. Don't use a nymph unless you want 90% of your catch to be whitefish.

If the weather is hot for an extended spell, the trout will head for the deep water or the tributaries.

See the Rivers in General section for more August fly fishing tips.

For more on August tactics and flies, see the Rivers in General report. See the Salmon River, Upper report for current conditions, hatches, guides, and other information.

Selway River

What to Expect in August:

This is not a good option for August. If you are in the area and feel obliged to fish here, look for trout in the tributaries and use an attractor pattern with yellow, red, or orange body, such size 8-10 Clarks Stoneflies, size 12-14 Humpies, Royal Wulffs, Trudes, etc.

See the Rivers in General section for more August fly fishing tips.

For more on August tactics and flies, see the Rivers in General report. See the Selway River report for current conditions, hatches, guides, and other information.

Silver Creek

What to Expect in August:

Look for trico duns and spinners on the water each morning. The hatch begins around 7:30-8:00 a.m. A CDC Biot Spinner or organsa-winged spinner pattern works well.

Tiny blue-winged olives may also be present during or after the trico emergence. Silver Creek's rainbows and browns sometimes prefer blue-winged olives over tricos when both are available. So if the trout are ignoring your trico patterns, try size 22-24 blue-winged olive imitations.

You'll find Callibaetis hatches in the slow sections this month, as well as adult damselflies.

Hoppers can draw fish to the surface during afternoon hours. A Parachute Hopper imitates this big bug and has an attractive low profile. An outrageous fly such as a Turcks Tarantula can also be effective in August. Toss your hopper near overhead cover, such as floating moss or weed beds, and wait for a big brown trout to slam it. Beetle imitations are another good option this month; see Meeting the Late Summer Challenge for some patterns and tips.

Sculpin imitations can take large trout here, so it doesn't hurt to carry a few and try them out.

During hot weather periods, Silver Creek sometimes has voluntary closures in the morning hours on the Conservancy water. That's because the plants suck all the oxygen out of the water; the dissolved oxygen content plummets for several hours and trout would be seriously stressed if they were caught and released during those times.

As on other spring creeks, you may need specialty spring-creek patterns to do well here. Non-locals may be best off to visit a local shop such as Lost River Outfitters or Silver Creek Outfitters and find what's working best. Then buy you flies there.

See the Rivers in General section for more August fly fishing tips.

For more on August tactics and flies, see the Rivers in General report. See the Silver Creek report for current conditions, hatches, guides, and other information.

Snake River, South Fork

What to Expect in August:

You might find some golden stoneflies around at the beginning of the month. These should be gone by the end of the first week in August, but you might still find trout that will take an imitation from force of habit. Later in August, a good option is the short-winged stonefly, or so-called summer stone. Skate an imitation across the surface near the bank. And hang on!

Size 16 pale morning duns will be hatching this month. Bring imitations in different silhouettes: emerger, upright dun, cripple, etc. On any given day, trout can have a definite preference for one over the other.

Be prepared for mahogany dun hatches, too.

Yellow sallies can still be found early in the month. Caddis (mornings and evenings), and hoppers, beetles, and ants round out the bug picture. You might want to select something other than the standard patterns so you can show those South Fork trout something they haven't seen too often.

The reliable hopper/dropper combo (hopper pattern with a 24-inch leader tied of the hook bend; put a Sparkle Pupa, Copper John, or Pheasant Tail on the other end) will make you a two-threat angler.

If you're after brown trout, a streamer is a good option.

Hot weather will slow the fishing. It seems to particularly affect caddis and PMD hatches. Fishing can also be up-and-down if the water level is fluctuating.

See the Rivers in General section for more August fly fishing tips.

For more on August tactics and flies, see the Rivers in General report. See the Snake River, South Fork report for current conditions, hatches, guides, and other information.

St. Joe River

What to Expect in August:

The St. Joe is a good choice in August. Most fly anglers like the area above Avery because it's catch-and-release only. Fish aren't huge, but they're abundant.

Hoppers, ants, and beetles are good choices in August. Many anglers love their Chernobyl Ants and Chernobyl Hoppers. They take trout, but I've watched hundreds of supposedly gullible westslope cutthroat reject these foam-bodied creations. If it's not working, try a lower-floating fly, such as a Parachute Hopper.

Look for evening caddis activity. Size 16-18 patterns, such as Elk Hair Caddis, Parachute Caddis, etc., work well. Attractor patterns such as yellow or orange Stimulators or Humpies are another choice. Hopper/dropper combinations, with a size 16-18 Pheasant Tail or Hares Ear on the dropper, are productive at this time of year.

Subsurface, a Cased Caddis can be productive in August, especially in the morning. Copper Johns in red, copper, or green are also useful. A small black streamer is another good subsurface option.

Another morning option for later in the month is a spruce moth imitation. These terrestrials often fall onto the water when their wings are heavy with morning dew. A size 8-12 white or blond Elk Hair Caddis will imitate them.

A size 18-20 cinnamon ant imitation is also useful at this time of year; a strike indicator can help when fishing that small dry fly.

While dry fly fishing is fun, the bigger fish are more likely to respond to a subsurface fly.

See the Rivers in General section for more August fly fishing tips.

For more on August tactics and flies, see the Rivers in General report. See the St. Joe River report for current conditions, hatches, guides, and other information.