For related historical program documentation see: archive.org/details/AerialForestInsectAndDiseaseDetection... Johnson, J. 2016. Aerial forest insect and disease detection surveys in Oregon and Washington 1947-2016: The survey. Gen. Tech. Rep. R6-FHP-GTR-0302. Portland, OR: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection. 280 p.