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Fishing ForecastFishing Report

A Look at Autumn Waters

By September 12, 2008April 14th, 2018No Comments


Last weeks report dealt with the types of insects one can expect to see in abundance over the next few weeks. In keeping with this theme of what one may find on the river, this week we will look at water types and general fish behavior for the fall months.


With all our area waters beginning to pick up in the catch rate category, it is time to get serious. The fall can be some of the season’s best fishing, but it is also the shortest window of opportunity left in the year.

Starting with the time of day, the autumn insects tend to keep bankers hours and there is no need to rush to the water before 9:30 or 10:00 a.m. What one may see during the course of the afternoon in the coming week or two can vary from the leftover summer bugs, like Tricos, to the newer bugs of the season like Red Quills. It is best to be armed with all your summer flies right now.

Expect to see strong hatches into the month of October. When we begin to reach the truly low light levels of the fall, the fishing windows will become incredibly short and the hatches more intense. By late October, with the first dustings of snow, and certainly by November, things will slow dramatically, although anglers with the right fly – namely the H and L Variant – will be able to search the surface waters until winter truly sets in.

For now, start late in the day and finish late in the day. Start bringing an extra jacket as the evenings should begin to cool off quite a bit. The Fall Baetis are normally associated with blanket hatches. The late morning, to early evening occurrence of these insect can bring every fish in the river to the surface. Look for these hatches on Silver Creek, the Big Wood, The Big Lost, and especially the South Fork of the Boise.

Water Type

In the fall, fish can be found in different parts of the pool, depending on what is hatching. If the blanket Baetis hatches are on the water, then it is time to concentrate on the tailouts and slick part of the runs. Looking behind logjams and other structure is also a great place to see fish come out for this midday snack. The calmer and glassier the water, the better.

When anglers encounter the Red Quill (Hecuba) it is a good time to concentrate on the fast water at the head of the runs. The insect can be hard to see in the fast water, despite its size, but there will be no mistaking the fish that are practically leaping out of the water to catch the insect.

If you see no fish working in the heads or tails of the pools, then stop and take a careful inventory of the run you are about to fish. It is not uncommon for the fish to pre-stage for these hatches and you may be able to find big fish lurking in shallow, obvious water.

When looking for the October Caddis, anglers should be blind fishing through shallow, boulder strewn runs. If you are seeing lots of their shucks, the adjacent water is a good place to search. You won’t find fish rising to big hatches of this bug, but you may find greedy fish looking for a quick meal.

Finally, the Mahogany Dun can be found randomly throughout Silver Creek and this event will occur from top to bottom. Some of the strongest hatches are often found way down stream where we normally fish the early season Brown Drake. It may take a bit more cool weather for this bug to show in good numbers, but that time is coming soon.


This terrestrial insect is out in force, and as more and more of the grass browns and dies, the continued migration toward the waters edge should make for great hopper fishing. Plan on seeing this bug until the first significant frost kills them. The Hoppers are mature now, so throw big patterns when imitating this bug.

Strike Indicators

With the surface activity waning over the next few weeks, fishing the nymph will become more and more important. Here is some great advice: With the falling light in September, the glare on the water will become harsher and harsher. The leaves will also begin to change and the river will fill with yellow and orange foliage. The best thing you can do now is to go and get some black colored strike indicators! The black will silhouette against the glare on the surface and will also stand out amongst the brightly colored leaves.

General Autumn Advice

The fishing windows are going to be closing soon, so try to plan your outings in advance. You may find yourself with only a few strong hours of fishing, so take advantage of these times and don’t beat yourself up the rest of the time. Keep in mind, for safety sake, it is hunting season, so wear bright colors on the river, and it is also time for the Moose to go into the rut. If you see a Bull Moose on the river, get away, they become very territorial and ornery this time of the season.

Enjoy the fall. Some of the seasons best fishing is about to happen with the seasons fewest amount of anglers on the water. Take a camera, enjoy the turning leaves and fish hard!