The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.
I think we have a winner! :) Leptophlebia, come on down!
I think Eric called it first...Cudos Eric.
Spence
There's noticeable venation (possibly pigmented) in the wings too, something I don't think we see in other three tailed mays -Yes?
I guess I should have also mentioned, there is a stream about half mile from the pond and also a large lake. After re-posting I googled Leptophlebia and saw a Youtube video of the nymph and hatching that looks very close to my mayfly. http://www.youtube.com/watch?v=XDTMFVHxXLk
Here is an example of what I believe is a male of the same species from NH:
http://bugguide.net/node/view/184905/bgimage