In the 1950s, the US feared a Russian invasion via Alaska—so the government trained regular folks, from fishermen to trappers, as secret agents. The plan involved coordination by J. Edgar Hoover's FBI, the CIA, and the military, the AP reports based on hundreds of partially-redacted documents obtained via the Government Attic. At the time, the FBI feared Russia would take aim at cities in what was then a US territory: Anchorage, Fairbanks, Nome, and Seward were thought to be at risk. "The military believes that it would be an airborne invasion involving bombing and the dropping of paratroopers," a document notes.
So the US readied what it called "stay-behind agents" in an operation dubbed "Washtub," among other names. These agents would hide in bunkers packed with food and communication equipment and report to the government on Russian movements, the AP notes. Officials recognized the high risk of the mission and planned for backup agents outside Alaska who could be deposited in the territory by plane. The program was active from 1951 to 1959, a government historian says, and though the Russians didn't invade, "the survival caches served peacetime purposes for many years to come," she wrote last year.