An 11 month investigation was undertaken to determine the nature of the flow system feeding Davis Spring. Davis Spring was monitored for stage, temperature and conductivity. Milligan Creek, a major infeeder to the system was also monitored. Quantitative and qualitative dye traces were performed to establish travel times through the system as well as further define drainage basin boundaries.From tracer analysis, storm pulse travel time analysis and hydrograph peak analysis Davis Spring was determined to be an open flow conduit during most of the year. Exceptions may occur during the winter-spring when intense rain and meltwater may fill the system. Increased winter-spring discharge appears to flush out nearly all stored water in the system. Once removed, conductivity rises until the next winter when the cycle repeats. MilliganCreek was found to be the closest major tributary of Davis Spring. Tracer travel times from Milligan Creek vary from 15 days at baseflow to 4 days during flood conditions. A large discrepancy was discovered between the Milligan Creek discharge the expected discharge for its catchment area.Additionally, a water budget for the period revealed unusually high evapotranspiration (80%) for the basin. Several possibilities exist for these discrepancies, and are discussed.By utilizing previous and recent tracer tests a linear trend of distance to transport time was established for baseflow conditions. The exception to this was Wood Sink. A similar trend was not observed under flood conditions because travel time increases proportionally with precipitation.

Entrance pit temperatures respond very quickly when atmospheric conditions are appreciably colder than existing air in Crowder Cave; temperature trends in the two rooms seldom lag more than 1-3 hours behind. Despite similar timing, the amplitude of temperature response in the large room is markedly less than in the small room, presumably because of a 35-fold difference in room volume. The amplitude of temperature change decreases and mean temperature increases with distance from the mouth of the large room. More characteristic of typical cave conditions, temperatures near the end of a narrow 85 m long side passage varied little (9.8° to 10.6°C) over the last 4.5 years. Crowder Cave data show the interplay between density-driven cold-air flow, karst topography, and cave geometry lead to variability in winter conditions that may give rise to very different bat hibernacula conditions in a single cave. The ecological significance of cold air traps associated with sinkholes may be profound, both as climate change indicators and for a potential role they may play in the course of the ongoing white-nose syndrome (Pseudogymnoascus destructans) epidemic.

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