This yellowish dragonfly is rather large with wide black shoulder bands and black abdomen with yellow marks. It is easily recognized by the unusually long spines on the back legs.
Common throughout eastern United States and southeastern Canada, this species is usually found at medium to large rapid streams, rivers, windswept lakes and ponds with rocky shores. It is widely distributed throughout northern two-thirds of Wisconsin.
In Wisconsin, the typical flight season is early June to late August.