Mature Frémont cottonwoods (Populus fremontii) line Southern Arizona’s San Pedro River beneath puffy clouds. Named for explorer John C. Frémont, these trees are a common sight along the San Pedro, the last free-flowing major desert river in the American Southwest. | Tim Fitzharris
After a night of heavy rain, morning sun illuminates low clouds in the broad, forested valley of Boneyard Creek in the White Mountains. The creek, east of Big Lake, empties into the East Fork of the Black River. | Joel Hazelton
Assorted wildflowers grow at the base of a fire-charred juniper along the Joe’s Canyon Trail at Coronado National Memorial. This moderate hiking trail, which includes Montezuma Pass and Coronado Peak, is one of five at the monument, which is along the U.S.-Mexico border. | Randy Prentice
Summer’s transition to fall is reflected in multicolored maple leaves in Garden Canyon, a destination in Southern Arizona’s Huachuca Mountains. The trunks in the background are those of Arizona sycamores (Platanus wrightii), known for their mottled bark. | Gurinder Singh
A blooming New Mexico locust (Robinia neomexicana) mingles with aspen trunks and bracken ferns in the Blue Range Primitive Area of Eastern Arizona. This tree is known for its delicate flowers and for its vigorous root sprouting, which gives it the ability to quickly regrow after a forest fire. | Jack Dykinga
Tall ponderosa pines stand amid other evergreens in a foggy scene on Spruce Mountain, part of the Bradshaw Mountains in Central Arizona. Spruce Mountain is home to a picnic site that, at 7,700 feet, is the highest-elevation recreation site on the Prescott National Forest. | Laurence Parent
False hellebores, also known as corn lilies, anchor a view of a dense forest of spruce trees along the West Baldy Trail. This 14-mile (round-trip) trail in the White Mountains features many such forest views as it ascends to near the summit of Mount Baldy, the range’s highest peak. | Joel Hazelton
