Laurel and Grass, Spence Field, Great Smoky Mountains National Park, Tennessee, June 28, 1968

Hemlock Branches, Great Smoky Mountains National Park, Tennessee, June 30, 1968

Nisqually Glacier and Avalanche Lilies, Mount Rainier, Washington, August 2, 1975

Nisqually Glacier and Avalanche Lilies, Mount Rainier, Washington, August 2, 1975

Noctilucent Clouds Over Mount Baker, Washington

Noctilucent Clouds Over Mount Baker, Washington

Tupelo Trunk and Water, Congaree, South Carolina, October 25, 1969

Agave lechuguilla, Big Bend National Park, Texas, May 21, 1950

Surf on Sea Cliff, Oswald State Park, Oregon, July 16, 1975

Maples and Firs, Hoh Rain Forest, Olympic Peninsula, Washington, July 24, 1975

Maples and Ferns, Hoh Rain Forest, Olympic Peninsula, Washington, July 24, 1975

Sage and Grass, Succor State Park, Oregon, July 10, 1975

Marsh Grasses, Malheur National Wildlife Refuge, Oregon, July 11, 1975

Sand Dune and Grass, Oregon Dunes, Oregon, July 14, 1975

Mixed Woods, Trillium Gap Trail, Great Smoky Mountains National Park, Tennessee, May 9, 1968

Rock Crevice at Low Tide, Cape Arago, Oregon, July 13, 1975

Drift Stump and Dead Trees, Cape Meares, Oregon, July 16, 1975

Airplane View, Congaree Swamp in Flood, South Carolina, April 19, 1969

Cactus Blossoms, Big Bend National Park, Texas, May 21, 1950

Brook, Oswald State Park, Oregon, July 16, 1975