Emerald Ash Borer detected in Denver threatens millions of trees

In the United States, the Emerald Ash Borer (EAB) has been confirmed in Denver, Colorado, marking a significant moment for the area. This invasive insect was identified by experts from Colorado State University and Denver's Office of the City Forester on June 17, 2025. The presence of EAB poses a serious threat as it has already caused widespread devastation to ash tree populations across 37 states and parts of Canada, impacting communities significantly financially. Denver is home to about 1.45 million ash trees, with 330,000 ash trees located specifically within the city limits. The city's forestry department has acknowledged the potential for dramatic changes to the Front Range landscape due to the presence of EAB, which aligns with trends observed in other affected regions where the insect has decimated ash populations. In anticipation of such an event, Denver's Parks & Recreation Department has been proactive in preparing the community. Since 2016, the Office of the City Forester initiated the