Aldo Leopold published two important works on phenology, one a research report (Ecological Monographs 17: 81-122.) and the other a popular book (A Sand County Almanac). Both publications reflect the results of Leopold’s 1936-1947 observations of a wide range of ecologically important seasonal events at a specific location, Leopold’s “Shack” in Sauk County, Wisconsin. I will discuss Leopold’s life-long phenological record-keeping from an ecological perspective and explore his objectives, both professional and personal. Leopold’s family participated in the record-keeping at the Shack, and after a hiatus of 29 years, in 1976 Leopold’s daughter, Nina Leopold Bradley, took the lead in resuming the phenology project. 
Results/Conclusions

An analysis of these long-term phenological data revealed patterns of change in the ecological community that could be correlated with climate change (Proc. Natl. Acad. Sci. USA. 96: 9701–9704). The Leopold tradition of keeping phenological records provides an example of how similar approaches to data collection could be incorporated into long-term, site-based ecological studies. I will use the Leopold data to illustrate the types of ecological insights that can results from observations of many biological and physical events at a single location. These insights could not be easily derived from observations of a few select species over a wide geographic area, as is the focus of several current phenology projects.