Tan Caddis Overview
- Family: Caddis
- Size: 8-13mm (Size 14-16)
- Emergence: Late June through early August
- Emergence Time: Sporadic during the day, concentrated at dusk
Many Montana rivers boasts an extremely heavy Tan Caddis hatch from late June through early August, sometimes later. They really show in the evening, and can blanket the rivers around Missoula on the Blackfoot River, Rock creek and the Clark Fork River. They appear on the Bitterroot River, but not always in such great numbers. Tan Caddis can also be found flying in small numbers throughout the day. They are a prime evening fly on Rock Creek and the Blackfoot, Missoula’s faster moving rivers that favor a Caddis hatch. There are multiple species hatching, anywhere from a size 12 through 16, all imitated by the same flies in different sizes.
Fly Fishing The Tan Caddis Hatch
When you see so many caddis on the surface, it’s easy to tie on the dry. But think about this. If there are that many caddis flying around on the surface, imagine how many larva and pupa are amongst the rocks in the river! At the Missoulian Angler Fly Shop, we monitor our fly sales very carefully. We can tell you we don’t sell anywhere near enough Caddis larva and Caddis pupa. If there’s a lot of adults, there’s a lot of sub-surface bugs!! That means the trout are eating the larva and pupa all year long. Again, our sales of caddis larva and caddis pupa doesn’t match the food source.
Don’t sleep on the sub-surface Caddis. Smart anglers know how prolific the larva and pupa are. Swinging a soft hackle or a Caddis pupa before the evening hatch can be unbelievably productive, as the swinging action replicates the emerging pupa almost perfectly.
The adult Caddis is one of the best searching patterns in the Missoula area. Caddis are coming off all day, and an Elk Hair Caddis will often move fish when nothing else is going on. Again, that goes back to how many Caddis are in the area. They don’t get the ink that PMD’s and Golden Stones get, but the Caddis is an extremely important food source for the trout.