The short version The archive turns up 107 records, most of them around Grand Canyon. 2 are confidently dated; the other 105 are educated guesses — about as precise as it sounds. All are free to use.
Alpine Valley Resort or Mountain Lodge, Early Color Film, circa 1950s 1948–1958 Aerial View of Bay and Waterfront, Mid-20th Century 1948–1965 German River Town at Dusk, circa 1950s 1948–1958 Mountain Pass Through Alpine Forest, Mid-20th Century Kodachrome 1945–1965 Limestone Quarry or Strip Mine, Mid-20th Century American West 1940–1970 Suburban Waterfront, Midwest Lake City, circa 1950s 1945–1960 Industrial Waterfront, Florida, 1940s-1950s 1940–1955 Mediterranean Coastal Inlet with White Limestone Cliffs, circa 1950s 1945–1960 Tourists at a Mountain Gorge with Cascading Waterfall, Early Color Photography 1940–1955 Manhattan at Night, circa 1940s-1950s 1940–1955 Rural Homestead with Crepe Myrtles, American South, circa 1940s-1950s 1940–1955 Formal Garden with Italian Cypress and Weeping Trees 1940–1960 Thatched House with Stream and Ivy, Britain, circa 1940s–1950s 1940–1955 Pine Forest and Stone Tower, Mid-20th Century American Landscape 1940–1960 Birch trees and lake, Canadian Shield region, autumn 1940s–1950s 1945–1955 Flower Show Display Garden, Mid-20th Century 1945–1965 Rural riverside homestead, American Midwest, mid-20th century 1940–1960 Sandy bottom creek with winter trees, mid-20th century 1945–1965 Captive Lion, Mid-20th Century Zoo or Menagerie 1940–1970 Azalea Garden in Pine Forest, American South, circa 1940s–1950s 1940–1955 Waterfall in Dense Forest, Kodachrome Slide, circa 1940s-1950s 1940–1955 Mountain Lake with Passenger Liner, circa 1950s 1945–1965 Lava Field with Birch Forest, Northern Landscape, Mid-20th Century 1945–1965 Neoclassical Building Approached Through Overgrown Garden, Mid-20th Century 1945–1965 Will Rogers Shrine of the Sun Dedication or Event, 1940s 1940–1949 Autumn Riverbank with Dead Log, ca. 1940s-1950s 1940–1955 Fleet of Orange National Park Tour Buses, Pacific Northwest Mountains, c.1950s 1948–1962 Coastal lagoon with beached boat and mangrove forest, Southeast Asia, circa 1950 1945–1965 Snow-Patched Mountain Range with Forested Valley, circa 1950s 1945–1965 Waterfall in Conifer Forest, Pacific Northwest, circa 1950s 1945–1965 Forest Canyon with Stream, Early Color Photography 1945–1965 Estate Garden with Formal Borders, Mid-20th Century 1945–1975 Institutional flower bed display, mid-20th century 1945–1965 Well Shelter in Rural Orchard, Mid-20th Century 1945–1970 Mangrove Channel, Hand-Tinted Kodachrome, circa 1940s 1945–1955 Mountain Valley Landscape, Mid-20th Century 1940–1970 Tropical River Valley with Dense Jungle Canopy, Southeast Asia, mid-20th century 1945–1970 Desert Wildflowers and Cacti, American Southwest 1940–1949 Atoll at Horizon, Pacific, 1940s-1950s 1940–1955 Bat roosting under eave, mid-20th century 1940–1965 Swimmers in Towed Rope Line, Lake or Sound, 1950s 1945–1965 Forest Canopy Study, circa 1950s 1945–1965 Memorial Plaque, Coastal Location, mid-20th century 1940–1970 Wooded Waterside Clearing, Mid-20th Century 1945–1970 Hydroelectric Dam Spillway in Operation, Mid-20th Century 1940–1965 Civic Monument and Domed Building from Riverbank, Mid-20th Century 1945–1965 Chalk Cliff Face with Coastal Vegetation, British Channel Coast 1945–1975 Alpine Avalanche Research Installation, Mid-20th Century 1945–1959
certain inferred low confidence