Rocky Mountain Region

U.S. Forest Service
Rocky Mountain Region
740 Simms St
Golden, CO 80401
303-275-5350

Telephone for the
Hearing Impaired
303-275-5367

Each year during the summer and early fall, aerial surveys are conducted to map forest insect and disease activity in forested areas of Region 2. We use aerial surveys because of the ability to monitor forest health conditions over large areas much more efficiently and economically than other methods. An observer in the aircraft records areas of activity either by drawing the affected area on a map or using a new digital system that incorporates a touch screen and GPS technology (Fact sheet on digital sketch mapping system, PDF, 240 kb). Aircraft used for these flights are typically small high-wing planes such as the Cessna in the photograph to the right. Surveyor from State cooperatoring agencies assist the Forest Service observers in surveying the forests lands.

Aerial Survey Aircraft; photo courtesy of W. Ciesla

Mountain Pine Beetle mortality in Ponderosa Pine; photo courtesy of W. Ciesla

The surveyor looks for certain characteristics to distinguish the trees species and the type of damage that has occurred. These characteristics or "signatures" include the shape of the crown of the tree, which is used to identify the tree species, and the color of the trees, which indicates the type of insect or disease activity. For example, bark beetles will result in the death of the tree causing the needles to fade in color to a yellow or straw color and then turn red. The photo to the left shows bark beetle mortality. In contrast, defoliators remove some of the foliage, resulting in a stand of trees with a discoloration, such as a gray, red, or yellow tinge.

2008 100K Quad Maps

2007 100K Quad Maps

2006 100K Quad Maps

2004 100K Quad Maps

2005 100K Quad Maps

2003 100K Quad Maps