This field guide is designed for streamside identification of aquatic insects commonly found in small, wadeable streams. It is intended to support studies where the goal is to identify aquatic insects in the field and return them to the stream unharmed. There are many reasons for conducting non-lethal bioassessment. It may be logistically simpler and quicker to return specimens to the stream rather than bringing them to the lab for identification, some groups may not want to preserve insects, or in many cases the characteristics that are most indicative of a particular invertebrate family may be best exhibited by a live specimen.