Hatch profile
Tricorythodes spp.
Water-temperature trigger
Top fly patterns
Tiny black-bodied mayfly. The spinner fall — not the dun emergence — is the main event. Look for clouds of spinners over flat water at sunrise.
Best rivers
Pennsylvania
Spring Creek
Jul 25 – Sep 5 · heavy
Pennsylvania
Letort Spring Run
Jul 25 – Sep 5 · heavy
Pennsylvania
Yellow Breeches Creek
Jul 25 – Sep 5 · heavy
Pennsylvania
Falling Springs Branch
Jul 25 – Sep 5 · heavy
Pennsylvania
Little Juniata River
Jul 25 – Sep 5 · heavy
Virginia
Mossy Creek
Jul 25 – Sep 5 · heavy
Other rivers with Trico activity
Bield: Fish watches USGS water-temp gauges for your home water and pings you when conditions hit the 60–75°F trigger window.
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