My experience has been that the Blue Quills start hatching earlier, last longer, and are more numerous than the Gordons. If you see fish actively rising, I would recommend a BQ pattern. Fact is, during any mayfly hatch you can fish an unweighted nymph and pick up fish just as many, but it's just not as fun. When I see fish pick off duns, that's what I aim for, foolish though it may be. I like the cut wing thorax style with the split tails for my mayfly duns, originated my Marinaro. Flyfishers Paradise has them, if you don't tie. (www.flyfishersparadise.com
, but you'll need to order the catalog.) They're in PA, but these bugs are universal throughout the Appalachian chain.