By Zach Lazzari

Hatches are all about the timing. When you get it right, the fly fishing can be flat-out epic. Picture clouds of insects plummeting to the water where every big trout in the river is waiting with an open mouth. On some rivers, these mega hatches happen annually and on others, it’s a once every seven years type of occurrence. 

Get your calendar out and start planning to catch the biggest hatch events of the year:

Mother’s Day Caddis 

Timing is anything but exact for this western hatch as it often coincides with runoff flows. When you catch it just right however, the number of bugs is immense and the fish go absolutely crazy. Focus on the last two weeks of April and the first week of May for this hatch in the Rocky Mountain states. Southwest Montana, Wyoming and Colorado have notable hatches. The Yellowstone River is well known for having a serious explosion of Mother’s Day Caddis. Get out your favorite elk hair caddis and get ready to skate it over your favorite runs.

Salmonflies

You just can’t go wrong with these huge bugs and the hatch takes place on a bunch of amazing rivers. The Deschutes River in Oregon has an early spring hatch while Montana, Wyoming and Colorado typically see bugs coming around the end of May and lasting through mid to late June. The Gunnison River Gorge has one of the biggest salmonfly hatches around and it flows through a remote canyon that requires a multiple day float trip. Many anglers will start fishing the big nymphs as they crawl towards the shoreline. When the hatch begins, giant orange stoneflies are crashing on the water. Fish a giant dry fly like a sofa pillow or foam salmonfly imitation and hold on tight because the big fish are looking towards the surface.

Hexagenia Mayfly

These massive mayflies are often bright yellow and they hatch in large numbers, bringing every trout to the surface. The hatch happens just before dark, leaving a short window of opportunity with visibility. Continuing to fish into the darkness is a common approach to capitalize on the feeding fish. The hatch occurs during the summer months with late June and early July being prime time in the midwest. Michigan has some excellent Hex hatches on rivers like the AuSable and Manistee Rivers. California’s Fall River also has a major hatch.

Spruce Moth 

Spruce moths look very similar to caddis but they are non-aquatic insects that bring trout into a feeding frenzy. The timing is also perfect during the late summer when other hatches are winding down and the action is slow otherwise. The moths actually live in the spruce and fir trees but they come down to the water where they are susceptible to trout. Late August and September have the bugs out in big numbers and the fish go crazy for the high calorie meal. This is a Rocky Mountain hatch so think Western Montana, the Green River in Wyoming, Alberta, Colorado and New Mexico.

Green Drake

Another giant mayfly, Green Drakes are a special hatch that can turn a trout river on fire in an instant. The hatch is not reliable by any means so prepare to spend some time on the water in order to catch the best flurries of action. It’s a summer hatch but the big bugs prefer high humidity days to keep their oversized wings hydrated. The best action often comes during days with a light summer rain shower. You will find the bugs dispersed throughout the Rocky Mountains, Pennsylvania and into Arkansas on famous waters like the White River.

Tricos

The tiny bugs can create some of the biggest hatches of the year and tricos are a favorite for technical fly anglers. The tiny black specs hatch in abundance during the late summer and they love slow moving sections of river. The trout will line up to selectively sip on the individuals and clusters of insects. Bring your A-game because presentation is absolutely critical. It’s not uncommon to find pods of trout sitting in mere inches of flatwater where the tricos congregate.

Cicadas

They don’t come every year but when the plague of cicadas hatch, trout go wild. Cicadas are terrestrial and depending on the variety, they will only hatch every 17 years. The Green River in Utah is famous for having cicada hatches and the area hosts a diverse variety of cicada broods. Each variety of brood has a different life cycle so you can expect a light hatch at the least and in some years, major hatches that have cicadas covering the water.

Zach Lazzari is a fly fishing guide and an outdoor writer based in Montana. Zach has fished and guided in Alaska, Colorado and Patagonia. Zach is also the blogger behind The Busted Oarlock.