In 1997, the TV Guide ranked this episode number 98 on its "100 Greatest Episodes of All Time" list.
In the control room, the console against the odd-looking wall behind the men is that same console used for the O.B.I.T. machine in O.B.I.T. (1963).
This is one of the very few episodes in 60s fantasy television that utilized stop-motion animation. The process was simply too expensive and time consuming for the limited television budgets and filming schedules of the time.
The ghost town of Morgue, California, was founded in 1859.
Burt Reynolds turned down the part of Ben Garth.