USDA Forest Service:
1945. Walter J. Buckhorn climbing tree to put up spray plot marker. Hemlock looper control project. Clatsop County, Oregon.
USDA Forest Service:
1945. Buckhorn putting up spray plot marker. Hemlock looper control project. Clatsop County, Oregon.
USDA Forest Service:
1948. Walter J. Buckhorn shooting a line-gun to mark aerial spray block boundaries. Western spruce budworm control project. Kinzua, Oregon.
USDA Forest Service:
1948. Walter J. Buckhorn shooting a line-gun to mark aerial spray block boundaries. Western spruce budworm control project. Kinzua, Oregon.
USDA Forest Service:
c.1950. Aircraft markers for aerial spraying.
USDA Forest Service:
1965. Pandora moth test spray - plot marker balloon. Chemult Ranger District. Fremont-Winema National Forest, Oregon.
USDA Forest Service:
1974. Aerial spray application marker. OR/WA/ID Douglas-fir tussock moth control project.
USDA Forest Service:
1985. Aerial marker balloon. Gypsy moth eradication project. Lane County, Oregon.
USDA Forest Service:
1985. Releasing aerial marker balloons. Gypsy moth eradication project. Lane County, Oregon.
USDA Forest Service:
1985. Aerial marker balloons with rigs. Gypsy moth eradication project. Lane County, Oregon.