Williamsonia lintneri is a rare dragonfly species restricted to southern New England and some northern states. In 1999, I tested the hypothesis that upland development around wetlands reduces habitat suitability for W. lintneri through increased nutrient runoff. I examined 27 wetlands and analyzed water quality and depth data, the composition of aquatic invertebrate assemblages, and land use patterns. Sites where W. lintneri was present did not differ in water quality from sites where it was absent (i.e., null sites). However, W. lintneri sites had significantly deeper levels of water throughout the summer, were dry for shorter periods of time, and had significantly lower levels of development in the surrounding uplands than did null sites. These results suggest that both hydrologic cycle and upland development are important in limiting the local distribution of this species.