Tricos can be a hatch to remember on the Missouri

Early August reliably brings a hatch of an insect about 1/8-inch long that absolutely drives trout into a feeding frenzy.

So, why would even the biggest trout in the stream get excited about a tiny mayfly that requires a size 22 hook to imitate?

Easy. Insects of the Genus Tricorythodes hatch in such phenomenal numbers that not only will they completely carpet a stream from bank to bank but, in flight, dense clouds can actually create shadows on sunny days.

I’ve seen trico hatches that create what look like dust devils but I’ve never experienced what I saw last weekend.

I left Great Falls at 5 a.m. and a few minutes after 6 I was standing in the Missouri River near Craig.

I was alone on a memorable very early morning. Deer drinking. Little smoke. Pastel colors. No wind. No hatching insects. No rising fish. Just quiet.

As I fished I noticed a few spent tricos floating by. Then more. And more. And more.

I resisted the temptation to re-rig to 5X tippet and a trico fly. I’ve played that tiny fly game before and, more often than not, go fishless.

I stayed with my favorite brown trout streamer on a sink-tip line and caught several very nice rainbows.

Then I noticed the entire surface, everywhere I looked, was carpeted with trico spinners!

But the image I’ll never forget was looking downstream and seeing what looked like backlit dust clouds created by several 18-wheelers on a gravel road.

Tricos! By the zillions!

Half hour later the flighted tricos were gone. And so were the fish.

Jerry Smalley’s Fishful Thinking column appears weekly in the Hungry Horse News.