above: LTRR Research Assistant Devin Petry dates a large cross-section from the Rincon Mountains

right: the location of the tree is marked with a red dot on this map of Tucson and the surrounding mountains (map courtesy of the WALTER project)

A Tree for Posterity

For five centuries this ponderosa pine lived on the slopes of Mica Mountain in Saguaro National Park (the red dot on the map below). It finally died from drought stress in 2002 and came down in the Helens II fire in 2004. Two cross-sections were retrieved by the Park and transported to the LTRR.

It took three people to heft this brute onto the work bench. LTRR Research Assistant Devin Petry prepared the sample and has tentatively dated the pith at around 1500, shortly after Columbus stumbled onto this continent.

The LTRR and dendrochronology labs around the world prepare samples like these for public display so we can share the lessons and beauty of such natural wonders.