The Big Thunder Mountain Railroad ride made its Disneyland debut in September of 1979. As you might imagine the ride was advertised aggressively on TV sets – at least in Southern California. I can remember the excitement surrounding the opening and waiting in very long lines once I eventually made it to the park and had a chance to hop on. You’ll also notice that in the 70s Disneyland was generally only open Wednesday through Sunday during the off-season.
Check out a 30 second spot from ’79 below.