A glacial moraine along the Old Mammoth Road near the north entrance of Yellowstone National Park.

Flt-tip pen on paper, 7.375 x 8.125 inches, 1978.

Tower Falls on Tower Creek near the Yellowstone River.

Felt-tip pen on paper, 8.5 x 10.625 inches, 1978.

Morning light on the Yellowstone River at campsite 1Y1.

Pencil, watercolor and white ink on yellow calligraphy paper,         1979.

A view of the Yellowstone River as it approaches the Hellroaring stock bridge.

Pencil and white ink on yellow calligraphy paper, 8.875 x 12, 1979.

The Gardner River below Osprey Falls within Sheepeater Canyon.

Pencil and white Prisma pencil on green pastel paper, 9.5 x 12 inches, 1979.

Rock outcrops above the banks of the Missouri River, near Great Falls, Montana.

Pencil on paper, 9 x 12 inches, 1980

Cow camp by a traihead that exits the canyon of the Escalante River in Utah.

Pencil on newsprint, 9 x 12 inches, 1980.

Granite boulders and sculptured rock with Ponderosa in Tokopah Valley, Sequoia National Park.

Pencil on paper, 9 x 12 inches, 1980.

Granite walls above Bubbs Creek along the trail decending from Junction Meadow to Kings Canyon, Kings Canyon National Park.

Pencil on newsprint, 9 x 12 inches, 1980.

A surviving snow bridge in spring melt, north of Granite Pass in Kings Canyon National Park.

Pencil on paper, 9 x 9.5 inches, 1980.

Old, decaying trunks of Western Junipers along the trail descending from Granite Pass to Simpson Meadow.

Pencil on paper, 9 x 12 inches, 1980.

Granite wall above the Middle Fork of the Kings River.

Pencil on toned paper, 9 x 12 inches, 1980.

Bridal Veil Falls in Yosemite Valley, Yosemite National Park.

Pencil and white Prisma on toned paper, 9 x 12 inches, 1980.

The Robson River passing a tilted block of limestone below Valley of Thouand Falls in Mount Robson Prov. Park.

Pencil on paper, 9 x 12 inches, 1980.

A hanging glacier above the steep north wall of Valley of Thousand Falls.

Pencil and white Prisma on toned paper, 9 x 12 inches, 1980.

The terminal end of Robson Glacier below Mount Robson.

Pencil on paper, 9 x 12 inches, 1980.

Stepped ice of glacier flowing around Hounds Tooth in the Purcell Range.

Pencil on paper, 9 x 12 inches, 1980.

Old bridge over Chalk Creek above Fillmore, Utah.

Pencil and white chalk on paper, 9 x 12 inches, 1982.

Badlands of the Two Medicine Formation west of Choteau, Montana.

Pencil on paper, 9 x 12 inches, 1982.

The Gorge of Dispair above the floor of Tehipite Valley.

Pencil on paper, 9 x 12 inches, 1982.

The floor of Tehipite Valley a few days after high water and flooding, Kings Canyon National Park.

Pen and ink on watercolor paper, 7.5 x 10 inches, 1982.

Story Hills, looking west across the Gallatin Valley, near Bozeman, Montana.

Pencil and felt-tip pen on paper, 7 x 9.75 inches, 1985.

The Berkeley Tower above Berkeley campus, San Francisco Bay beyond.

Pencil and felt-tip pen on paper, 7 x 9.75 inches, 1985.

A group of paleontologists remove a plastered block from the Ghost Ranch Coelophysis Quarry, near Ghost Ranch, New Mexico.

Pencil on paper, 9 x 12 inches, 1985.

The Red Deer River near East Coulee, Alberta.

Pencil on paper, 9 x 12 inches, 1986.