Beaver’s prep school
Was Fallbrook East or West or North of where they were in Mayfield? I would say that Mayfield might be in the Great Plains or something.

Well, my guess is East.

And Aunt Martha was arriving by plane. In a much earlier episode Beaver and Wally visited her, and took a train. At that time I think she lived in Riverside, which probably is supposedly not that far from Mayfield (you probably would not send those younger boys on an extremely long train trip). And Ward drove Beaver there one other time.

But Martha could conceivably flown in on a short hop trip.

Maybe we can find out what state they were in,where is there a riverside?

LOL

Never looked closely at that--clever touch--if you're going to Hadley City, it's straight through, but on the way back, we need to detour to Burns Junction on the way. I'm surprised whatever set designer was responsible for this didn't say, "Who's gonna have time to read this whole thing, which isn't on-screen more than 5 seconds?"

A big airport for 12 gates.

There is a Crystal Falls, Mayfield, Elmhurst, Bellport and Riverside in California. There is a Burns Junction near the Oregon California border.

Fun Fact:
Oregon is known as The Beaver State.

Bus Station - not airport

there are 46 States with a Riverside