- Paleoclimate Tool
- The Laboratory of Tree-Ring Research, The University of Arizona
http://ltrr.arizona.edu/about/treerings
- NGDC-NOAA Paleoclimatology Program
http://www.ngdc.noaa.gov/paleo/paleo.html
- Recent Drought Assessment of Northern Arizona, Kurt Kipfmueller
http://www.ltrr.arizona.edu/~msalzer/Salzer_Kipfmueller2005.pdf
- Cool-season precipitation reconstruction data from this project are available for download from the NOAA Paleoclimatology Branch: