Carbon isotopes are valuable tools for determining the overall ambient conditions under which trees incorporate seasonal growth, and can act as indicators of periods of environmental stress, including salt water intrusion and droughts. When coupled with traditional dendrochronological analyses, carbon isotopes can potentially relay a high-resolution history of localized hydrologic conditions, and highlight intervals of increased tropical cyclone activity and precipitation frequency as well as long-term trends in freshwater availability. Studies of this nature are scarce for South Florida trees, in spite of the extreme relevance implied by the current focus on global climate change and accelerating rates of local sea level rise that have important implications for future freshwater management. Tree ring records spanning three decades from two sites, Pinus elliottii var. densa from northwestern Big Pine Key and Taxodium ascendens from the C-111 Basin in Taylor Slough (Florida Everglades), have been compared with the annual precipitation records and some preliminary isotopic data has been collected. The final results of the study will yield a thirty year history of the fluctuations in precipitation patterns, intervals of storm frequency and the timing and distribution of saltwater stress; these can result in proxies that can be applied to extended periods in time or areas where recorded climate records are absent.