Environmental monitoring at the Hanford Site began in 1944. Historically, the targets of environmental monitoring included agricultural products, soil, vegetation, air, surface and ground water, wildlife, fish, and other aquatic organisms. The monitoring activities identified and quantified the contaminant contributions from Hanford Site operations.
In addition to contaminant monitoring, population metrics for several species were monitored as indicators of site health, these include the number of chinook salmon redds and Canada goose nesting success. The isolation of the Site provided refuge for rare or threatened species including the bald eagles, ferruginous hawks, and populations of shrub-steppe birds. Monitoring these species provides data on temporal and spatial trends. Finally, in the early 1970's Rocky Mountain elk migrated to the Site and have flourished. Population monitoring documented the establishment of this population.