Philippe Clement / Mistletoe (Viscum album) in Poplar tree (Populus sp) La Brenne, France

Konrad Wothe / Fremont Cottonwood (Populus fremontii) with fall color, Bosque del Apache National Wildlife Refuge, New Mexico

Konrad Wothe / Fremont Cottonwood (Populus fremontii) amid gypsum dune fields, White Sands National Park, Chihuahua Desert, New Mexcio

Tim Fitzharris / Rio Chama with Cottonwood (Populus sp) trees and other riparian species growing along banks, New Mexico

Tim Fitzharris / Cottonwood (Populus sp) with the Carson Range in the background, Nevada

Tim Fitzharris / Quaking Aspen (Populus tremuloides) and Spruce (Picea sp) forest with snow dusting, Rocky Mountains National Park, Colorado

Tim Fitzharris / Maple (Acer sp) and Cottonwood (Populus sp) trees in autumn, Zion National Park, Utah

Tim Fitzharris / Fremont Cottonwood (Populus fremontii) trees growing in the Chihuahuan Desert at White Sands National Park, New Mexico

Tim Fitzharris / Fremont Cottonwood (Populus fremontii) tree single tree in desert, White Sands National Park, Chihuahuan Desert New Mexico

Tim Fitzharris / Cottonwood (Populus sp) fall foliage with Magdalena Mountains behind, New Mexico

Tim Fitzharris / Cottonwood (Populus sp) and Cranes, autumn foliage, Bosque del Apache National Wildlife Refuge, New Mexico

Tim Fitzharris / Oak (Quercus sp), Cottonwood (Populus sp) and Willow (Salix sp) leaves in fall colors

Tim Fitzharris / Cottonwood (Populus sp) trees and Willows, fall foliage, Bosque del Apache National Wildlife Refuge, New Mexico

Tim Fitzharris / Cottonwood (Populus sp) trees, fall foliage, Carson Valley, Nevada

Tim Fitzharris / Maple (Acer sp) and Cottonwood (Populus sp) autumn foliage, Zion National Park, Utah

Tim Fitzharris / Maroon Bells at Maroon Lake with Cottonwood (Populus sp) trees, Colorado

Tim Fitzharris / North Fork of the Virgin River flanked by Cottonwood (Populus sp) trees, Zion National Park, Utah

Tim Fitzharris / Cottonwood (Populus sp) tree and Coyote bush (Baccharis vanessae) with sand dunes, Monument Valley, Arizona

Matthias Breiter / Quaking Aspen (Populus tremuloides) and Birch (Betula sp) trees in winter, Manley Hot Springs, Alaska

Gerry Ellis / Fremont Cottonwood (Populus fremontii) tree in Chihuahuan Desert, White Sands National Park, New Mexico

Jeff Foott / Fremont Cottonwood (Populus fremontii) trees in autumn, Grand Staircase-Escalante National Monument, Utah

Jeff Foott / Fremont Cottonwood (Populus fremontii) trees in autumn, Grand Staircase-Escalante National Monument, Utah

Jeff Foott / Fremont Cottonwood (Populus fremontii) trees in autumn, Grand Staircase-Escalante National Monument, Utah

Jeff Foott / Fremont Cottonwood (Populus fremontii) trees in autumn, Grand Staircase-Escalante National Monument, Utah

Jeff Foott / Fremont Cottonwood (Populus fremontii) trees in autumn, Grand Staircase-Escalante National Monument, Utah

Jeff Foott / Fremont Cottonwood (Populus fremontii) trees in autumn, Grand Staircase-Escalante National Monument, Utah

Jeff Foott / Fremont Cottonwood (Populus fremontii) trees and rock formation, The Castle, Capitol Reef National Park, Utah

Jeff Foott / Fremont Cottonwood (Populus fremontii) trees and rock formation, The Castle, Capitol Reef National Park, Utah

Jeff Foott / Fremont Cottonwood (Populus fremontii) trees and rock formation, The Castle, Capitol Reef National Park, Utah

Jeff Foott / Fremont Cottonwood (Populus fremontii) trees in autumn, Navajo Dome, Capitol Reef National Park, Utah

Jeff Foott / Fremont Cottonwood (Populus fremontii) trees in autumn, Navajo Dome, Capitol Reef National Park, Utah

Jeff Foott / Cottonwood (Populus sp) trees in autumn, Glacier National Park, Montana

Jeff Foott / Fremont Cottonwood (Populus fremontii) trees and rock formation, The Castle, Capitol Reef National Park, Utah

Jeff Foott / Fremont Cottonwood (Populus fremontii) trees in autumn, Bentonite Hills, Capitol Reef National Park, Utah

Jeff Foott / Cottonwood (Populus sp) tree and rock formation in autumn, The Castle, Capitol Reef National Park, Utah

Tim Fitzharris / Cottonwood (Populus sp) trees, Kebbler Pass, Colorado

Tim Fitzharris / Sunburst and autumn Cottonwood (Populus sp) trees, Kebbler Pass, Colorado

Tim Fitzharris / Fremont Cottonwood (Populus fremontii) tree, White Sands National Park, New Mexico

Tim Fitzharris / Cottonwood (Populus sp) trees in autumn, Blue River, Colorado

Tim Fitzharris / Cottonwood (Populus sp) trees along lake, Pahranagat National Wildlife Refuge, Nevada

Tim Fitzharris / Cottonwood (Populus sp) trees and mountains, Zion National Park, Utah

Tim Fitzharris / Cottonwood (Populus sp) trees and mountain, Zion National Park, Utah

Yva Momatiuk & John Eastcott / Cottonwood (Populus sp) trunk, Utah

Yva Momatiuk & John Eastcott / Balsam Poplar (Populus balsamifera) leaves, Grand Teton National Park, Wyoming

Suzi Eszterhas / American Beaver (Castor canadensis) feeding on Cottonwood (Populus sp), Martinez, California

Suzi Eszterhas / American Beaver (Castor canadensis) eight-week-old kits feeding on Cottonwood (Populus sp), Martinez, California

Suzi Eszterhas / American Beaver (Castor canadensis) eight-week-old kits feeding on Cottonwood (Populus sp), Martinez, California

Suzi Eszterhas / American Beaver (Castor canadensis) feeding on Cottonwood (Populus sp), Martinez, California

Donald M. Jones / Dall's Sheep (Ovis dalli) rams feeding on Quaking Aspen (Populus tremuloides), Yukon, Canada

Jeff Foott / Cottonwood (Populus sp) tree in hole, Grand Staircase-Escalante National Monument, Utah

Jeff Foott / American Beaver (Castor canadensis), Grand Teton National Park, Wyoming

Jeff Foott / Lodgepole Pine (Pinus contorta) and Quaking Aspen (Populus tremuloides) trees in fall, Grand Teton National Park, Wyoming

Jeff Foott / Lodgepole Pine (Pinus contorta) and Quaking Aspen (Populus tremuloides) trees in fall, Grand Teton National Park, Wyoming

Jeff Foott / Paintbrush (Castilleja sp) flowers and Quaking Aspen (Populus tremuloides), Grand Teton National Park, Wyoming

Jeff Foott / American Beaver (Castor canadensis) feeding on Quaking Aspen (Populus tremuloides), Grand Teton National Park, Wyoming

Jeff Foott / American Beaver (Castor canadensis) reinforcing dam, Grand Teton National Park, Wyoming

Jeff Foott / American Beaver (Castor canadensis) feeding on Quaking Aspen (Populus tremuloides), Grand Teton National Park, Wyoming

Jeff Foott / American Beaver (Castor canadensis) feeding on Quaking Aspen (Populus tremuloides) in pond, Grand Teton National Park, Wyoming

Jeff Foott / American Beaver (Castor canadensis) feeding on Quaking Aspen (Populus tremuloides), Grand Teton National Park, Wyoming

Jeff Foott / American Beaver (Castor canadensis) feeding on Quaking Aspen (Populus tremuloides), Grand Teton National Park, Wyoming

Jeff Foott / Quaking Aspen (Populus tremuloides) trees in fall with Fireweed (Chamerion angustifolium) seedheads, Grand Teton National Park, Wyoming

Matthias Breiter / Alaska Moose (Alces alces gigas) female feeding on Aspen (Populus tremuloides) leaves in autumn, Denali National Park, Alaska

Matthias Breiter / Alaska Moose (Alces alces gigas) female feeding on Aspen (Populus tremuloides) leaves in autumn, Denali National Park, Alaska

Matthias Breiter / Alaska Moose (Alces alces gigas) female feeding on Aspen (Populus tremuloides) leaves in autumn, Denali National Park, Alaska

Matthias Breiter / Alaska Moose (Alces alces gigas) female feeding on Aspen (Populus tremuloides) leaves in autumn, Denali National Park, Alaska

Yva Momatiuk & John Eastcott / Cottonwood (Populus sp) leaf on moss in autumn, Nisga'a Memorial Lava Bed Provincial Park, British Columbia, Canada

Yva Momatiuk & John Eastcott / Cottonwood (Populus sp) trees on hillsides in autumn with morning mist, British Columbia, Canada

Tim Fitzharris / Cottonwood (Populus sp) tree felled by American Beaver (Castor canadensis), Grand Teton National Park, Wyoming

Tim Fitzharris / Cottonwood (Populus sp) tree along lake, Granite Dells, Watson Lake, Arizona

Donald M. Jones / Rocky Mountain Elk (Cervus canadensis nelsoni) bull chewing on Aspen (Populus sp) bark, Canada

Matthias Breiter / Balsam Poplar (Populus balsamifera) new growth, Kenora, Ontario, Canada

Tim Fitzharris / Cottonwood Tree and Sandhill Crane (Grus canadensis) flock in pond, Bosque del Apache National Wildlife Refuge, New Mexico

Sebastian Kennerknecht / Sandhill Crane (Grus canadensis) pairs under Fremont Cottonwood (Populus fremontii) tree at sunrise, Bosque del Apache National Wildlife Refuge, New Mexico

Colin Monteath / Willow (Salix sp) and Cottonwood (Populus sp) trees in fall colors with Lake Pukaki, Mount Cook, and Mount Tasman, Mackenzie Country, South Canterbury, New Zealand

Yva Momatiuk & John Eastcott / Cottonwood (Populus sp) trees in fall colors along creek, Zion National Park, Utah

Yva Momatiuk & John Eastcott / Cottonwood tree branches against sandstone walls, Grand Staircase-Escalante National Monument, Utah

Tim Fitzharris / Cottonwood (Populus sp) trees, fall foliage, Carson Valley, Nevada

Jeff Foott / Cottonwood (Populus sp) covered with snow in winter, Zion National Park, Utah

Jeff Foott / Cottonwood (Populus sp) tree, Havasu Falls, Havasupai Indian Reservation, Grand Canyon National Park, Arizona

Jeff Foott / Cottonwood (Populus sp) trees in fall, Grand Tetons, Grand Teton National Park, Wyoming

Jeff Foott / Cottonwood (Populus sp) trees in fall, Grand Tetons, Grand Teton National Park, Wyoming

Jack Dykinga / Aspen (Populus tremuloides) and Birch (Betula sp.) trees in autumn colour reflecting in Talbot Lake beneath the Miette Range, Jasper Provincial Park, Alberta, Canada. September.

Jack Dykinga / Autumn coloured Aspen (Populus tremuloides) and Birch (Betula sp.) leaves among White fir (Abies amabilis) cones on the forest floor, Figure Eight lake Provincial Park, Alberta, Canada. September.

Jack Dykinga / Aspen (Populus tremuloides) and Birch (Betula sp.) trees in autumn colour reflecting in Talbot Lake beneath the Miette Range, Jasper Provincial Park, Alberta, Canada. September.

TOM MANGELSEN / Aspen (Populus sp.) trees standing on a hillside in snow, backlit by sun breaking through clouds, Lamar Valley, Yellowstone National Park, Wyoming, USA. February.

TOM MANGELSEN / Willows (Salix sp.) and Cottonwood trees (Populus sp.) along a mostly frozen Lamar River during a blizzard, Yellowstone National Park, Wyoming, USA. February.

Kirkendall-Spring / Frost-covered Cottonwood (Populus sp.) trees in snowy landscape, Lamar Valley, Yellowstone National Park, Wyoming, USA. January, 2022.

Kirkendall-Spring / Cottonwood (Populus sp.) trees in autumn foliage along the Lamar River, Lamar Valley, Yellowstone National Park, Wyoming, USA. September, 2021.

Kirkendall-Spring / Cottonwood (Populus sp.) trees in autumn foliage surrounded by early autumn snow along the Lamar River, Lamar Valley, Yellowstone National Park, Wyoming, USA. October, 2019.

Kirkendall-Spring / Cottonwood (Populus sp.) trees reflecting on the Lamar River in winter, Lamar Valley, Yellowstone National Park, Wyoming, USA. February, 2015.

David Welling / Cottonwood trees (Populus fremontii) and young Willows (Salix sp.) growing beside river, Lamar valley, Yellowstone National Park, Wyoming, USA.

Jack Dykinga / Timelapse of Aurora Borealis (KP 7) moving over Figure Eight Lake. The shoreline has Birch (Betula sp.), Aspen (Populus sp.) and Conifer (Pinophyta sp.) trees on it. Provincial Park, Alberta, Canada....

Jack Dykinga / Aurora borealis in the night sky with autumnal colored Aspen (Populus sp.) and Birch (Betula sp.) trees illuminated by moonlight, in marshland around Obed Lake, Alberta, Canada. September, 2023.

Jack Dykinga / Aurora borealis in the night sky with autumnal colored Aspen (Populus sp.) and Birch (Betula sp.) trees illuminated by moonlight, in marshland around Obed Lake, Alberta, Canada. September, 2023.

Jack Dykinga / Long Canyon at the confluence with The Gulch, lined with peak colored Cottonwood trees (Populus sp.) and Sage brush (Artemisia sp.) in the foreground, Grand Staircase-Escalante National Monument, Utah...

Jack Dykinga / Large flock of Snow geese (Anser caerulescens) and Sandhill cranes (Grus canadensis) congregating in corn fields surrounded by ancient Cottonwood trees (Populus sp.) under sun-lit clouds, San Bernadin...