Southwest Idaho Fly Fishing Report

Grab your rods, it's time to fish!

After a slow start caused by a solid runoff, summer fishing is finally starting to heat up. With flows continuing to drop on most of the rivers in Southwest Idaho, we anticipate it will keep getting better. Faced with high waters and unexpected tailwater releases (*headshake*Owyhee*cough*), most anglers have looked for more stable waters. We’ve got a few recommendations for you.

Boise Main

Let’s start with a report from our own backyard. Fishing has improved in town and if you’re looking to wet a line on the Boise Main, you’ll have the most success during early mornings or late evenings, after the majority of floaters (and all their trash) have left the river behind to hit the bars. Be on the lookout for early-morning, midday and evening PMD and caddis hatches that will have fish looking up with a chance to get them to the surface. While you may pick up a stocker bow on a dry, expect to use nymph caddis pupa/midge droppers to get into bigger fish. This year the river seems to have a healthy population of white fish, so if you’re looking to just bend the rod, search for them close to shore and at the tail end of runs and pools. The bigger bows, browns and red sides remain elusive, though perseverance and some luck may get you hooked up.

Middle Fork Boise

While we love the Middle Fork of the Boise River, getting there is always a pain in the butt. It’s a great place to go if you’re just out there to catch fish, but don’t except to land monsters and be sure to watch out for rattlers along the shore. If you do head up the Middle Fork, we recommend taking Blacks Creek Road, stopping off at the Y-Stop and picking up your favorite local beer (you know, Natty Light or a fine American pilsner) and dropping down the back way to avoid the madhouse you’ll inevitably encounter near Lucky Peak or Arrowrock.  Whether you’re able to pick up fish or not, the river itself is absolutely beautiful. The water is gin-clear and good for wet-wading. Fish are hammering medium- to larger-sized indicators (i.e. size 10-14 caddis/stones/Dave’s hopper). We’ve caught a lot of 6-12 inch fish, but there are some bigger ones hiding out if you can find them. Smaller fish hit all day, but things really seem to turn on after about 1600 (that’s 4:00 p.m. in normal-people speak). It’s always a beautiful river to fish, just be safe driving up there. And if you’re in a hurry and decide to drive like a reckless jerk, don’t taunt the fishing veterans and shout obscenities all while passing people on a one-lane dirt road.

Upper South Fork Boise

Much like the Middle Fork Boise, the Upper South Fork Boise (yes I just said that), above Pine and Featherville, fishes well. We have a lot of fun catching a large number of smaller fish there, mainly on size 14-18 caddis/adams. Similar to the Middle Fork, the water is clear and perfect for wet-wading. Things really turn on after 1600 making it perfect for a cast-fish kind of evening where the fish are chasing shadows and using the rivers’ gorgeous structure. We even towed up a first-timer with us recently who caught something. If you’re looking to get away from some people, this may be the option for you. 

South Fork Boise

The South Fork of the Boise River is producing some really good fish. Long, all day floats are fun, but if you’re really looking to pick up fish, save it for the afternoon or evening. While there are good hatches going on throughout the day, the majority of the surface action happens after about 1630. Picking up fish on the surface is a little tough only because they are hitting small emergers in the last 3-6 inches of water. If you plan on throwing dries, size 12-14 caddis are working well. Look for shaded areas and overhangs for the bigger fish. 18-20 Adams also worked well. After talking to other folks on the river, we found that nymphing caddis in the riffles
and pocket waters seem to produced good fish.  And never forget, you can always throw a big nasty bug against the shore and sometimes stimulate a gorgeous rainbow to go airborne to raise the boats morale. 

Owyhee River

Back to that headshake and cough...
Earlier in the summer we had some amazing days on the Owyhee. The river was still low and green, and the fish were smashing BWOs, PMDs and small nymphs. Catches were big and healthy. But sadly, after the massive blowout, things have taken a turn for the worst. After floating it a couple of times and even giving it a solid few hours of wade-fishing, we came to terms that the Owyhee is no longer the wait for the size 20-22 PMD hatch and slam monster browns river that it used to be.
A local biologist took the time to talk to us about how the river’s ecological system has changed. The recent blowout relocated the silt, debris, dead carp and aquatic plant life that produces the large insect hatches we’ve seen in the past. While the insects have been quick to return, the feeding habits of the fish have changed, and they’ve gone from being selective to seeking out soft targets for calories. What that means for us feather-huckers is that we can’t count on the standard yellow PMD hatch to bring fish to the surface. No more smashing big browns for us, for now. After talking more about the impacts of a massive tailwater blowout and the effects it would have on the fishery, we’ve concluded that, while the fish are most definitely still there, they’ve been pushed way down river. That’s why, if you read legitimate fishing reports from fly shops, you’ll hear-tell of folks picking up more fish below the tunnel.  All in all, throwing nymphs has really been most effective on this stretch. During midday, spit case PMD/BWO and caddis pupa have been successful. With the hottest part of summer approaching quickly, hoppers, ants and other nasty surface attractors thrown close to the bank will bring fish to the rise. Hit the river mid-week and give it a float if you can to beat the crowds and cover the most water in a short amount of time. Be on the lookout for rattlers, poison oak and poison ivy when putting in, taking out and wade fishing.  

The Icing

If you can’t tell, fly fishing has a special spot in our hearts, but bringing a fish to the net is just the icing on the cake.  The calm surroundings, gorgeous scenery and the company you choose to surround yourself with is truly the best part of the day. Not to mention the cold water feels great on tired knees and sore ankles. 

Take some time and enjoy what our state and its neighbors have to offer.  Be courteous and respect that others enjoy this world as well. Never miss an opportunity to say hello with a wave, a nod of the head or a lift of the hand from your steering wheel. If the time arises to converse, do so. Teach and learn from each other. Today you decided to fish. Who knows what tomorrow bring? Be safe, have fun and good luck out there.


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