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

Jack Dykinga / Fremont cottonwood trees (Populus fremontii) with autumnal leaves, Coyote Gulch,Grand Staircase-Escalante National Monument, Utah, USA.

Jack Dykinga / Cottonwood (Populus fremontii) trees in autumn at sunset, forming a sinuous line of yellow trees. Deer Creek Canyon, Grand Staircase-Escalante National Monument, Utah, USA, October.

Jack Dykinga / Cottonwood (Populus fremontii) trees forming a sinuous line of yellow trees at sunset, in Deer Creek Canyon, Grand Staircase-Escalante National Monument, Utah, USA

Jack Dykinga / Cottonwood (Populus fremontii) in autumn, Long Canyon, Grand Staircase-Escalante National Monument, Utah, USA. October 2013.

Daniel Heuclin / Rio Grande Cottonwood tree (Populus fremonti wislizenii) on a sand "pedestal" White Sands National Park. New-Mexico, USA, August 2009

Jack Dykinga / Fallen leaves of Boxelder {Acer Negundo} and Cottonwood {Populus fremontii) floating on pool in autumn with reflections of canyon walls, Lower Calf Creek Falls, Grand Staircase - Escalante National Mo...

Jack Dykinga / Havasu Falls with Fremont cottonwood trees (Populus fremontii) Havasupai Reservation, Arizona, USA

Jack Dykinga / Fallen leaves of Boxelder {Acer Negundo} and Cottonwood {Populus fremontii) floating on pool in autumn, Lower Calf Creek Falls, Grand Staircase - Escalante National Monument, Utah

Jack Dykinga / Fallen leaves of Boxelder {Acer Negundo} and Cottonwood {Populus fremontii) floating on pool in autumn, Lower Calf Creek Falls, Grand Staircase - Escalante National Monument, Utah

Jack Dykinga / Havasu Falls cascade behind Fremont cottonwood trees (Populus fremontii) glowing in reflected canyon light, Havasupai Reservation, Arizona, USA

Jack Dykinga / Lower Calf Creek Falls with Boxelders {Acer Negundo} and Cottonwoods {Populus fremontii) in the foreground, autumn colours, Grand Staircase - Escalante National Monument, Utah