Brain Food: The World’s Largest Alligator Juniper Tree

Apr 19, 2018

A massive alligator juniper tree near Prescott is believed to be the largest and oldest of its kind in the world. It’s survived hundreds, possibly thousands of years of fire and drought. Forester Ben De Blois says the tree’s unique growth pattern makes it hard to tell just how old.

The Granite Mountain Hotshots after they saved an ancient alligator juniper from a wildfire in 2013. A week later all but one of the crew was killed in another fire.
Credit Courtesy

“This tree in particular is difficult to date. It’s kind of a multi-stemmed specimen, so dendrochronology normally allows us to just take a core sample from a tree, you can date it pretty easily. This one because of the nature of the way it’s branching out, it’s really difficult to do that. And junipers, in particular, can be a harder one to date. Their rings are really difficult to see,” he says.

One of the most poignant chapters in the juniper’s life is that it was saved from fire in 2013 by the Granite Mountain Hot Shots, an elite group of wildland firefighters from Prescott. A week after they saved the tree, all but one of the crew was killed in the Yarnell Hill Fire.

“A lot of folks refer to it as the Granite Mountain Juniper Tree in commemoration of the Granite Mountain Hotshots. That’s one of the last major memories a lot of people have of the Granite Mountain Hotshots, so it’s a very special place to a lot of us. We actually erected a small memorial there. A tree can tell you a lot of history,” De Blois says.

This particular alligator juniper has been designated as an Arizona Champion Tree on the American Forests’ National Register of Big Trees. It’s a running list of the largest known trees in the United States.