JACKSON, Wyo. — With the autumn equinox signaling the start of fall this Monday, the valley has begun to glow with the yellow and gold hues of quaking aspens.
This time of year, aspens appear to shimmer when the sunlight dances on the yellow leaves.
On Sept. 17, Buckrail photographer Nick Sulzer caught the changing colors of the aspen leaves. According to Grand Teton National Park (GTNP), as days shorten and become cooler, the trees stop producing green chlorophyll, allowing yellow and gold pigments to emerge. Orange and red aspen leaves occasionally occur, but are less common than yellow.
Aspens can retain their color for several weeks, but temperature and moisture determine the intensity and duration of the colors, per GTNP.
“A wet growing season followed by dry, sunny autumn days with crisp, cool (but not freezing) nights seems to yield the best colors,” GTNP wrote on its website. “Unhealthy aspen stands are less likely to have vibrant colors whereas a healthy stand will have bright colors.”
A small hawk appeared to bask in the glow of the yellow, while taking a rest on a tree branch near the Gros Ventre River. Quaking aspens can be found near water, on mountain slopes or in a grove of evergreens.
