Cordulegaster erronea (Tiger Spiketail) is of conservation concern throughout much of its range; yet only a single study on the nymphs has been conducted, and many aspects of the species’ life-history are poorly understood. The present study evaluated the size, age structure, and density of Tiger Spiketail nymphs at a stream on the Schiff Reservation Natural Lands Trust (Schiff) in Mendham Township, Morris County, NJ. We investigated the habitat and surrounding landscape characteristics of this stream and a second stream containing Tiger Spiketails at Schiff. We collected and measured 137 Tiger Spiketail nymphs during this study—82 in the spring and 55 in the fall—representing pre- and postadult emergence. We found 24 exuviae along both study streams and an additional 8 exuviae along 3 other streams in New Jersey, Connecticut, and Delaware. We are aware of only 1 other published report of Tiger Spiketail exuvia, which documented a single specimen. Our data and habitat assessment indicate that the Tiger Spiketail has a long nymphal stage and may be dependent upon high quality, fish-free, perennial headwater streams flowing through extensive forests. This information may assist resource managers in developing conservation strategies and habitat-protection measures for this species.