`hammer' is a mayfly
an absoluteley eye blistering bright yellow mayfly,all yellow,wings, legs,all of it,i've researched it but i cannot I D it exactly,the reason i point out `all yellow' is there is a `hex' hatch on a nearby different river,they reportedly have grey wings,and a `heptagenia' doesn't seem to match the hatching criteria these `hammers' have,well,i've been to all sorts of match the hatch sites,mayfly central,etc,etc,still no positive i-d,but if you reference Trey Combs book;steelhead flyfishing and flies,there is a pattern called `A'ls Yellow Hammer,or al's special,i just started tying steelhead hairwings with all yellow materials,worked great!after an evening session where i cought 25-30 trout and two nice summer steelhead with one i proclaimed as i walked down the riffle and looked at the beat up fly,,hammer!,,,the hammer!,strait up,and i've tyed and used them ever since,these mays will hatch for months some years,size 6 give or take,my belief is since the man trey referenced actually lived on the banks of the Rogue in my section during the 30's he simply tyed an elaborate version to catch fishermen :tsk_tsk: ,they seem peculier to the area i live,upper middle Rogue,oh,and congratulations to your son on the six-pac!