The Trico is one of the smallest hatchable mayflies, a black-bodied, white-winged miniature whose summer-morning emergence and spinner fall draw trout to the surface in clouds of feeding fish.

The Pale Morning Dun is the dominant summer mayfly across the West.

The March Brown is the second major mayfly hatch of the spring season, typically following BWOs and overlapping with skwalas.

The Mahogany Dun is a small-to-medium fall mayfly with a deep reddish-brown body, color so distinctive it gives the species its common name.

The Hecuba is one of the largest mayflies of the fall, a russet-brown to mahogany-bodied dun that emerges just as October caddis activity is winding down.

The Green Drake is one of the year’s most-anticipated dry-fly hatches in the West.

The Gray Drake is a large, slate-gray mayfly that overlaps with the Western Green Drake but is more often fished as a spinner than a dun.

The Blue-Winged Olive is arguably the most important mayfly in trout fishing.