I took certain liberties with this cover by conflating the National Forest Service (an agency of the Department of Agriculture) and the National Park Service (an agency of the Department of the Interior). But given that The Ad Council intentionally gave Smokey a distinctive National Park Service hat, and that we are celebrating the centenary of the National Park Service itself this year, it seemed forgivable.
The cover shows before and after photographs of a portion of the Angeles National Forest damaged by a wildfire, overlaid with a "Smokey Bear" National Forest Service badge and set atop the flames of a forest fire. It is accompanied by the intro to the familiar slogan introduced in 1947: "Only YOU can prevent forest fires" (amended in 2001 to "wildfires").
The stamps are of President Theodore Roosevelt, who led the effort to create the National Forest Service and who signed the Antiquities Act that allowed the creation of the National Park Service (Scott #2218g); the mascot version of Smokey the Bear (Scott #2096); and the stamp issued for the semicentennial of the National Park Service in 1966 (Scott #1314).
It is postmarked with the 2016 DELPEX pictorial postmark featuring a "Smokey" hat to commemorate the centennial of the National Park Service.