October Caddis

Photo by Les Korcala

October Caddis Overview

  • Family: Caddis
  • Size: 15-17mm (Size 10-12)
  • Emergence: Mid September through October
  • Emergence Time: Afternoon

The October Caddis hatch in Montana signals that Fall fly fishing is here, and we need to make the most of the end of the fishing season! Montana’s last and largest caddis, the October Caddis can be upwards of 25mm long, making it the biggest caddis on the Blackfoot River, Rock Creek, The Bitterroot River and the Clark Fork River.

Fly Fishing The October Caddis

The October Caddis is not really a very strong hatch, yet it is a tremendous fly. It’s truly rare to find fish lined up and feeding on the October Caddis. But if you see an October Caddis fly by, and they are hard to miss as they go lumbering by, tie one on. Even if you’re not seeing them on the water, or haven’t seen a rise, the fish are looking for them, and will come up to take it. Sometimes, if the action is a little slow, it pays to skitter the October Caddis across the surface, imitating the natural laying her eggs. A little twitch or a full on skitter can elicit some monster strikes.

Subsurface, the October Caddis is a very well-known meal. With their size and abundance, the October Caddis is a favorite sub-surface target. Think about using an indicator, as there’s usually no pertinent fly that floats a nymph of that size. True, a hopper may drag a fish up once in a while, but the cold weather that moves the October Caddis often slows down the hopper action. Better an indicator with an October Caddis and BWO or Mahogany nymph pattern beneath. 

Without a consistent presence on the rivers, it’s easy to focus on the BWO’s and Mahoganies. But it doesn’t take a lot of October Caddis moving to bring fish to the surface. Make sure you have your October Caddis, and when you see one, make that move. Your fish count will go up.

Additional October Caddis Resources