Fly hatch chart for Coeur D’alene River in northern Idaho including fly hatch species, fly size, and peak months of activity based on historical data.

Hatch sizes and dates will vary from year to year based on weather conditions, water flows, and temperatures. In some years, hatch may be more or less prolific. Typically the biggest indicator of fly hatches is when temperature reach above 50 degrees.

Major Fly Hatches

Trout start surfacing in late winter early spring as the Coeur D’alene River comes to life with aquatic insects. Major spring hatches include midges, Blue-winged Olives (baetis), March Brown Mayflies, Stoneflies , and the Skwala Stonefly hatches the Coeur D’alene is known for.

As spring runs into summer a number of new hatches enter the scene including Salmonfly, Pale Morning Dun (PMD) Mayfly, Yellow Sally, Golden Stonefly, Green Drake, and caddis, which make up the majority of trouts’ diet during late spring early summer.

Other prolific hatches on the Coeur D’alene River, especially in the lower elevations, include Mahogany Duns, Yellow Quills, and Tricos. Important, but less prolific hatches include Golden Stonefly, Winter Stonefly and Little Yellow Stonefly.

While the Skwala Stonefly hatches are popular among anglers, they’re far less prolific and predictable than others. Anglers will find caddis hatches throughout the spring and fall with Little Black Caddis hatches in May, Spotted Sedge hatches in August, and the October caddis hatches in the late fall being the most prolific.

As with most of Idaho’s major river systems, terrestrial insects such as ants, beetles, and grasshoppers become a major food sorce for hungry trout come summer. Japanese Beetle, Carpenter Ant, and hopper imitations all get the trout biting early to late summer.

A few of the more effective flies to fish on the Coeur D’alene are sculpin and baitfish. Nymphing and fishing streamers tends to be the more effective method for trout fishing, although fishing dry fly is also productive during much of the season.