The timeline of this episode appears to take place in the 1960s. Doc and the Chief make reference to events from the 1950s as if they were not that long ago. Also, Richie's truck appears to be from the '60 era. A reference to the Grady daughters may place the timeline even later, as they would have died sometime around the winter of 1970-71.
Actress Adrienne Barbeau also appeared in "The Crate" story from the 1983 film Creepshow. The crate prop from that vignette can be seen during the opening credit sequence.