Gallery

Gretchen Fitzgerald, a forester with the U.S. Forest Service’s Columbine District, leads students from Colorado Timberline Academy through the forest looking for ponderosa pine trees infected with pine beetles near Rockwood north of Durango. Photo by Jerry McBride/Durango Herald

Gretchen Fitzgerald, a forester with the U.S. Forest Service’s Columbine District, cuts bark off of a ponderosa pine tree killed by pine beetles. Fitzgerald was explaining forest health to students from Colorado Timberline Academy near Rockwood north of Durango. Photo by Jerry McBride/Durango Herald

Gretchen Fitzgerald, a forester with the U.S. Forest Service’s Columbine District, explains how pine beetles damaged the bark of a ponderosa pine, eventually killing the tree. Fitzgerald was explaining forest health to students from Colorado Timberline Academy near Rockwood north of Durango. Photo by Jerry McBride/Durango Herald

Gretchen Fitzgerald, a forester with the U.S. Forest Service’s Columbine District, talks about ponderosa pine trees that have been killed by the pine beetle while explaining forest health to a group of students from the Colorado Timberline Academy near Rockwood north of Durango. Photo by Jerry McBride/Durango Herald

These ponderosa pine trees did not survive a pine beetle attack near Rockwood north of Durango. Photo by Jerry McBride/Durango Herald

A pine beetle taken from a ponderosa pine tree near Rockwood north of Durango. Photo by Jerry McBride/Durango Herald

This ponderosa pine tree successfully fought off pine beetles with sap until the tree was overrun, killing it and others near Rockwood north of Durango. Photo by Jerry McBride/Durango Herald

These ponderosa pine trees did not survive a pine beetle attack near Rockwood north of Durango. Photo by Jerry McBride/Durango Herald

As pine beetles move through the bark of ponderosa pine trees, they leave trails called galleries. Photo by Jerry McBride/Durango Herald