Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.
Your latter two educated guesses are good ones.
Methinks it's not Epeorus, Roger. (I'll reserve my hunch about what it is for now.)
-----Original Message-----
From: FlyFishing Entomology [mailto:FlyfishingEntomology@comcast.net]
Sent: Saturday, March 28, 2009 7:11 PM
To: levwood@*********
Subject: RE: What is this bug?
Hi Lev,
... The bug in your attached photo is a male mayfly spinner, and I believe it to be Cinygmula, perhaps C. reticulata.
Best regards,
Roger Rohrbeck