the Cleavers and why would she read about Wally and the Beaver's boat rescue in her local paper?

Most of the time she supposedly lives in Riverside, which we learn in one episode is a train ride away. Yet in a later episode she arrives in Mayfield by plane, I think. She could have moved, I guess.

Either way I doubt Beaver's boat rescue or eighth grade football catch would make her local paper.

Bus Trip

How many miles away and direction are they supposed be from Mayfield?

Season 2 episode 12, "The Visiting Aunts" Aunt Martha drives in for a morning visit, arriving from Riverside in time for lunch with the Cleavers.

Ward had already promised to drive Beaver to a carnival in Garden Grove, which he insisted he would still do, after Aunt Martha's visit had concluded.

Aunt Martha ends up staying til late afternoon, But Ward points out there is still time to go to the carnival since the carnival was open until 10 pm.

So, take an inventory of how many locations in the USA are within both a 4 hour drive from "Riverside" while also being within an evening's drive of "Garden Grove", and you narrow the field down considerably.