Here's a 1970s public service announcement for the USDA's Forest Service. Appears to be a recruiting ad, though this is not entirely clear. At the very least, the ad appears to be an opportunity to applaud the work of this federal agency. 

A man -- says his name is Bob McKey, or something similar -- sings among giant trees while playing a guitar. The man's folksy song has the following whimsical lyrics: "Products and fun, beauty for everyone. It’s national forest naturally. It’s natural green on the national scene. The forest ranger is the man to see."

The end of the PSA has the text: "Write: AMERICA'S NATURAL GREEN, USDA FOREST SERVICE, ATLANTA, GEORGIA 30309."