Spring Fishfly

Very cool find! I am pretty certain that this is a Spring Fishfly rather than a Dobsonfly. Though they are somewhat similar, female Dobsonflies have larger mandibles and a slightly different shape of body (especially noticeable in the head and thorax). Dobsonflies also don't sport that lovely yellow coloration where the wings meet the body that yours has. You can compare yours to this female Dobsonfly: http://bugguide.net/node/view/311398 Hope this is helpful.