BlueOak-CalifCentralValley-K.J.Anchukaitis_1.jpg

The width of the annual tree rings of blue oaks  in central California reflects how much winter rain falls each year. The same winter storms that water those oaks bring snow to California’s Sierra Nevada. (Quercus douglasii) The width of the annual tree rings of blue oaks in central California reflects how much winter rain falls each year. The same winter storms that water those oaks bring snow to California’s Sierra Nevada.