1. Our Fall Color Season GOES ON and on and on

Thanks to the Eastern Sierra’s varied elevations—from approximately 5,000 to 10,000 feet (1,512 to 3,048 m) — the trees peak in color at different times. Bishop, Inyo County and southern Mono County usually turn color first, with Mammoth Lakes, June Lake, Bridgeport and northern Mono County peaking by mid-October.

2. Which kind of trees will change color

Trees that change color in the Eastern Sierra include aspen, cottonwood and willow.

3. Good Timing

What makes the leaves know where to change colors is  the change in air temperature and decreased daylight.

4. Chlorophyll vs. other pigments

The reason we see fall colors is part of an annual cycle that begins in spring and summer: green chlorophyll pigments are active in cells and mask yellow, orange and red pigments of the leaves. The occurrence of fall colors is actually the disappearance of green chlorophyll!

5. Color intensity

Intensity of leaf color is determined by the air’s temperature and moisture. Warm, dry days and cool nights (under 45°F or 7°C) mean brilliant colors; rainy days and warm nights result in less intense coloration.

6. Color Parade

Different leaves have different predominant pigments called xanthophylls (yellows), carotenoids (yellows, oranges and reds), and anthocyanin (red). Anthocyanin is the result of trapped plant sugar, produced by the leaf when days are sunny and nights are cold. That's why some leaves turn deep crimson red, while others become so gold they seem to be lit from within like a lamp.

Excerpted from California's Eastern Fall Color Guide and Map.