Understanding the specific habitat requirements of reptiles during different life stages or seasons is critical to conserving viable populations. Northern Pinesnakes (Pituophis melanoleucus) are one of the few species that spend the winter in underground hibernacula, which they excavate themselves. We report on 26 years (1986–2011) of monitoring Pinesnake use at seven hibernacula in the New Jersey Pine Barrens. Our goal was to determine the frequency of repeated use, number of snakes present by year, disruptions of hibernacula, and the relationship between number of snakes present and the probability of occupancy of each hibernaculum in successive years. The overall goal was to determine the importance of protecting known hibernation sites regardless of whether they appear occupied in a given season. These data suggest that, if no snakes are observed entering a particular hibernaculum over a limited time period, it does not mean none are there or that none will use it in successive years. The variability in use suggests not only that predation and human disturbance can result in nonoccupancy the following year but that environmental and temperature-related conditions force snakes to have alternative hibernacula to reduce risk and ensure survival. Pinesnakes are listed as threatened by the New Jersey Department of Environmental Protection for many reasons, including habitat loss. There is continued pressure from developers to destroy habitat during development, including critical hibernation sites. The long-term use of specific hibernacula, even with periods of low or no use, suggests that these resources should be protected to provide a matrix of available overwintering sites.