As their name suggests, Clubtails have an enlarged tip on the end of their abdomens, giving them a club-like appearance. Not only is this species uncommon in New York State, but it is difficult to see due to its camouflaged coloration. The Rapids Clubtail is greenish yellow in color with blackish brown stripes and a blackish abdomen with yellow dorsal (top) and lateral (side) stripes (Needham et al. 2000, Nikula et al. 2003). They are 42-45 mm (1.7-1.8 inches) in length with a 31-34 mm abdomen. They have blue-green eyes and, as with all Gomphids, their eyes are separated dorsally. They have a slender abdomen with a widened "club" at the end and abdominal segments 8-10 are dark dorsally, with yellow, linear spots present on the top of the other abdominal segments. Yellow to gray-green stripes occur laterally on all abdominal segments. The male anterior hamule (the top pair of terminal appendages, consisting of hardened cuticle, which borders the genital pocket) is sickle-shaped and female sub-genital plate is thick and 1/7 as long as abdominal segment 9 and has a V-notch nearly to the base. They may be distinguished from other similar species by the following characteristics: Adults have a more prominent club and less yellow on the abdomen and completely black legs. Also, females have more yellow spotting on their abdomen.

Gomphid larvae spend much of their time burrowing into the substrate of streams and rivers where they are found. Adults are found perching on the ground, on emergent rocks in streams and rivers, or on leaf surfaces (Nikula et al. 2003). Adult females oviposit by tapping their abdomens onto the surface of swift-flowing water while simultaneously releasing eggs (Nikula et al. 2003, Mead 2003).

Rapids Clubtail larvae feed on smaller aquatic invertebrates and adults feed on insects which they capture in flight.