Counties most impacted in northwest Colorado in 2024: Garfield, Mesa, Pitkin
Piñon Ips beetle (Ips confusus) continues to attack piñon pine trees in northwest Colorado. This native insect has thrived in piñon-juniper forests that are experiencing low precipitation and warmer-than-average temperatures, which weaken trees. Compounds in the tree’s resin attract the beetle, so damage to trees from construction activities has also contributed to the spread of this insect.
Areas most impacted by this beetle in this part of the state include piñon-juniper forests in Glade Park and Gateway Canyon, south into Tenderfoot and Outlaw mesas, in Mesa County; the Cedaredge area of Delta County; and around Rifle and Glenwood Springs in Garfield County. Localized pockets of mortality are evident in parts of the Roaring Fork Valley leading into and around Aspen in Pitkin County.
Piñon Ips beetles rarely attack healthy trees, so managing for healthy stands of piñon pines is the best way to prevent an outbreak. Also, it is important to properly handle and dispose of cut trees and slash so they do not encourage the spread of beetles. Landowners should prune piñon trees from November to February when the beetles are inactive.
The Colorado State Forest Service offers science-based strategies and education to help landowners and public land managers address this insect, including a quick guide.
Counties most impacted in northwest Colorado in 2024: Eagle, Garfield, Mesa, Pitkin
Douglas-fir beetle (Dendroctonus pseudotsugae) remains atop the list of forest health issues for northwest Colorado. This beetle is a close relative of other native bark beetles, such as spruce beetle and mountain pine beetle, and inhabits mature Douglas-fir forests across most of the West. Levels of tree mortality from Douglas-fir beetle vary widely and occur in pockets, from a smattering of trees in some areas to near total loss of mature stands in others.
Years of drought have left Douglas-fir trees in northwest Colorado susceptible to outbreaks of this native bark beetle. The beetle heavily affected Douglas-fir forests in Eagle, Garfield, Mesa and Pitkin counties in 2024 and has increased activity in the Roaring Fork Valley since the Lake Christine Fire in 2018.
Pheromone packets attached to healthy trees are one form of treatment for Douglas-fir beetle. They act as a “no vacancy sign” by mimicking a chemical emitted by the beetles when they infest a tree. Other management strategies include thinning dense forests to reduce competition for resources, increasing individual tree vigor, and removing wind-thrown and already infested trees.
Counties most impacted in northwest Colorado in 2024: Eagle, Garfield, Grand, Jackson, Mesa, Moffat, Pitkin, Rio Blanco, Routt
Across higher elevations in northwest Colorado, subalpine fir trees continue to succumb to western balsam bark beetle (Dryocoetes confusus) acting alongside fungi that cause root decay. Drive over just about any mountain pass in this part of the state and you’ll notice trees impacted by this killer combo; they have a reddish tinge that can stick out in patches of healthy, green trees.
Locations in northwest Colorado most impacted by this beetle in 2024 include the Grand Mesa in Mesa County. The Rabbit Ears Range in Jackson and Grand counties and forests within the Flat Tops in Moffat, Routt, Rio Blanco and Garfield counties are continuing to experience an increase in intensity of beetle infestations. The Roaring Fork Valley leading to Aspen in Pitkin County and the Sawatch Range in Eagle County have seen notable tree loss in recent years. Berthoud Pass and the Vasquez Peak Wilderness in Grand County continue to experience heavy tree mortality from this bark beetle as well.
Aside from removing infested trees before adult beetles fly to new trees the following year, foresters have few management strategies to counteract these beetles due to the spotty nature of infestations and the low value of the wood to offset costs. In certain areas impacted by this decline, however, dead trees have been removed to address public safety issues and reduce wildfire risk.
A $1.23 million donation kickstarted fundraising efforts to transform the Michigan River Camp at the Colorado State Forest into a facility that offers place-based learning, training and research.
Working with many partners and across boundaries on nearly 1800 acres, foresters in the Steamboat Springs Field Office have managed critical work that’s reduced wildfire risk and benefited the local economy.
Staff at the Colorado State Forest pooled funding to carry out a crucial forest health project on about 600 acres of State Trust Lands in southeast Jackson County.
