Megaregions of the USA

It's fair to say that the USA has featured in the news quite a lot over recent weeks and months.

There have been various attempts over the years to subdivide the country into regions, often connected with the major cities.
Alasdair Rae and colleague Garrett Dash Nelson have produced a useful map of the USA for this purpose.
They're called Megaregions, and this interactive map allows you to explore them.

This article also names some of the areas. I remember hearing about Bosnywash and similar megalopolises years ago, now they seem to be spreading to become larger subdivisions of the states. Another example of how geography constantly changes.