Click on the link & it will show you a grid.
Click on an individual grid box (there is none for Houston, only Galveston & Bolivar [Boll-iv-er] Peninsula).
You then get a map that shows you a bunch of boxes with a tighter zoom; the boxes aren’t lined up edge to edge (they are gapped a bit).
Clicking on an individual box then loads a smaller copy on the R that’s the same map you just clicked & a larger image on the L (similar to about 4 clicks out on Google Maps).
You then click on THIS ‘4 click out’ map & it will load up a much larger image (you’ll have to scroll around to center things up once it’s fully loaded).
You can click in & out with a magnifying glass kind of mouser & change locations faster than scrolling around…
To go back to the start, use the BACK arrows on your screen OR just reload the original link.