A 650 year-old Douglas-fir stands just east of Dillon Reservoir. It and 15 other very old trees were sampled to develop the Dillon (DIL) tree-ring chronology, which has been used to reconstruct the annual flow of the Blue River.

Annual tree growth at lower elevations in Colorado is closely correlated with variations in precipitation, snowpack, streamflow, and drought indices. Thus, tree rings can be used to reconstruct records of these hydroclimatic variables for the past 300 to 750 years, or longer. For the TreeFlow project, we're developing new hydroclimatic reconstructions in partnership with water resource managers. This project is funded by the NOAA Office of Global Programs Climate Change Data and Detection Program and the NOAA/CIRES Western Water Assessment Program, a Regional Integrated Sciences and Assessments program. Work was also partially funded by the National Science Foundation (ATM-0080889).