Snow on Saplings with Black Tree Trunks, Great Smoky Mountains National Park, Tennessee, March 11, 1969

West Prong, Little Pigeon River, Great Smoky Mountains National Park, Tennessee, March 12, 1969

Flame Azalea, Laurel Falls Trail, Great Smoky Mountains National Park, Tennessee, May 10, 1968

Rhododendron maximum, Cades Cove Road, Great Smoky Mountains National Park, Tennessee, June 30, 1968

Heavy Frost on Trees, Newfound Gap, Great Smoky Mountains National Park, Tennessee, March 12, 1969

Heavy Frost on Trees, Newfound Gap, Great Smoky Mountains National Park, Tennessee, March 12, 1969

Beech Seedling and Hemlocks, Roaring Fork Road, Great Smoky Mountains National Park, Tennessee, March 13, 1969

Alpine Flowers, Mount Rainier, Washington, August 2, 1975

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

Noctilucent Clouds Over Mount Baker, Washington

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

Weathered Stump, Cape Meares, Oregon, July 16, 1975

Mount Adams and Dead Tree, Washington, July 20, 1975

Nisqually Glacier, Mount Rainier, Washington, August 2, 1975

Decaying Leaves, Congaree, South Carolina, October 27, 1969

Brook with Mossy Rocks, Trillium Gap Trail, Great Smoky Mountains National Park, Tennessee, May 8, 1968

Lichen and Moss on Rock, Clingman's Dome, Great Smoky Mountains National Park, Tennessee, May 11, 1968

Mountain Laurel, Laurel Falls Trail, Great Smoky Mountains National Park, Tennessee, May 10, 1968

Little Pigeon River at Chimneys, Newfound Gap Road, Great Smoky Mountains National Park, Tennessee, April 22, 1968

Cascade in Big Creek, Walnut Bottom Road, Great Smoky Mountains National Park, Tennessee, April 24, 1968