Swiss Family Chipmunks
S1:E20
1983
IMDb
Dave drags the Chipmunks unwillingly on a camping trip in the great out doors. When they finally arrive, the Chipmunks discover large footprints and think they are being followed by Bigfoot. Eventually they build a treehouse for Dave, when he falls and injures himself badly, and Alvin and Simon go in search for Big Foot.