Ha! It is isn’t it. The one episode where the family is going cross country in the wagon in the 1800s and one of the kids is sick. And the father goes to look for water and somehow he is transported to the future and he finds a diner and tells the waitress about his son and she gives him penicillin, and he accidentally leaves his gun behind and they find out it’s a gun from the 1800s.
A Hundred Yards Over the Rim:
https://en.wikipedia.org/wiki/A_Hundred_Yards_Over_the_Rim
(We watch the TZ marathon every Christmas week; never gets old.)
-JT