Gray's Arch, Red River Gorge, Kentucky, April 16, 1968

Gray's Arch, Red River Gorge, Kentucky, April 16, 1968

Temple of Yu the Great, Shaoxing, China, July 15, 1980

Temple of Yu the Great, Shaoxing, China, July 15, 1980

Lotus and Azolla, West Lake, Hangzhou, Zhejiang, July 14, 1980

Rose Petals on Beach, Great Spruce Head Island, Maine, July 1, 1971

Rose Petals on Beach, Great Spruce Head Island, Maine, July 1, 1971

Hay Fern, Chocorua, New Hampshire, October 13, 1953

Gray's Arch, Red River Gorge, Kentucky, April 16, 1968

Gray's Arch, Red River Gorge, Kentucky, April 16, 1968

Gray's Arch, Red River Gorge, Kentucky, April 16, 1968

Sunflowers and Sand Dunes, Great Sand Dunes National Monument, Colorado, September 10, 1976

Sunflowers and Sand Dunes, Great Sand Dunes National Monument, Colorado, September 10, 1976

Oak Forest, Pan Am Highway Below, Cerro de la Muerte Park, Costa Rica, March 15, 1984

Wind Clouds Over Dunes, Indian Springs, Colorado, September 12, 1976

Lichen on Brown Rock, Maroon Lake Area, Colorado, July 30, 1981

Sunset Clouds, Sleeping Rainbow Ranch, Capitol Reef National Park, Utah, August 28, 1963

Cloud Formations, Tesuque, New Mexico, July 1977

Aspen Forest with Yellowish Leaves in Foreground, Ashcroft Road, Colorado, September 17, 1959

Cottonwood Trees in New Leaf, near Red Wing, Colorado, May 21, 1975