The Flintstones - Season 6 - Eps 8: Rip Van Flintstone
Bored by his company picnic, Fred slips away to take a nap, and awakens twenty years later to discover that Barney has become millionaire B.J. Rubble, and that Pebbles and Bamm-Bamm have gotten married. Upon entering Wilma who is now living alone through Barney's largesse, Fred really awakens and realizes it was all a dream.
About The Flintstones

Title: The Flintstones
First Air Date: 1960-09-30
Last Air Date: 1966-04-01
Status: Ended
Rating: 7.427/10 (from 924 votes)
Language: EN
Seasons: 7
Total Episodes: 166
Network: ABC
Genres: Family, Animation, Comedy, Kids
Production Companies: Hanna-Barbera Productions, Screen Gems Television
Synopsis
The misadventures of two modern-day Stone Age families, the Flintstones and the Rubbles.
Cast

Alan Reed
Fred Flintstone (voice)

Mel Blanc
Barney Rubble (voice)

Jean Vander Pyl
Wilma Flintstone (voice)

Gerry Johnson
Betty Rubble (voice)

Don Messick
Bamm-Bamm Rubble (voice)