Tim Fitzharris / Fallen autumn colored Aspen leaves on the ground covered in dew droplets, Colorado

Tim Fitzharris / Autumn along Swift River, White Mountains National Forest, New Hampshire

Tim Fitzharris / Autumn foliage on Blue Ridge Range near Jumping Off Rock, North Carolina

Tim Fitzharris / Wild river in eastern hardwood forest, White Mountains National Forest, Maine

Yva Momatiuk & John Eastcott / Timber Wolf (Canis lupus) members of the pack in mock fight, Grizzly Discovery Center, Montana

Gerry Ellis / Colorful fall leaves around Hunting Creek, eastern hardwood forest, Catoctin Mountain Park, Maryland

Yva Momatiuk & John Eastcott / Autumn leaves changing color, Hurley, New York

Tim Fitzharris / Autumn leaf on boulder, Little River, Great Smoky Mountains National Park, Tennessee

Jim Brandenburg / Canoe bow with autumn trees, Discovery Lake, Superior National Forest, Minnesota

Jim Brandenburg / Timber Wolf (Canis lupus) juvenile in forest, Minnesota

Michael Quinton / Elk (Cervus elaphus) two males sparring in the fall, Yellowstone National Park, Wyoming

Jim Brandenburg / Raven Lake surrounded by autumn colored forest, Minnesota