Dying, Off, Color Pine Needles Normal in Autumn, Colorado State Forest Service

Ponderosa and lodgepole pines and some spruce and fir species Colorado shed older, interior needles as part of an annual growth cycle in September and October.

Conifers: Evergreen Trees and Shrubs - Acadia National Park (U.S. National Park Service)

Forests are reeling from climate change—but the future isn't lost

Why are my pine trees turning brown? - Christmas Trees

Leaf Peeps, Fall Colors Are Coming. Here's Where To Find Them In Southern Colorado

Colorado State Forest Service says off-color pine needles normal, not disease

Fading, Off, Color Pine Needles Normal in Autumn, Colorado State Forest Service

In what season do leaves fall off the trees? - Quora

Dying, Off, Color Pine Needles Normal in Autumn, Colorado State Forest Service

Expect Vibrant Fall Colors in Colorado This Year, Colorado State Forest Service

Evergreen Borer Beetles - Impact on Denver Properties

Colorado's peak 2021 fall colors have arrived; now is the time for leaf-peeping