lol, as a VA resident I like this idea
Several suggestions:
1 Northern VA: Northern VA is INCREDIBLY different than the rest of VA. Northern Virginia is mostly just Fairfax and Loudon Counties, the two big ones at the top of the dark red bonus. I would say make this its own small bonus. If you want to incorporate the historical sites, you also might want to blow up that region (see WWII Europe, several other maps) because a lot of Civil War stuff is there.
2 Impassables: definitely have Mountains between the orange/yellow regions and the whitish/light green/ a little bit of dark red regions. You can have 1 or 2 holes in the mountains if you want, but they're necessary to decrease all of the borders for all of the regions, etc. I would also have the rivers come pretty far in as impassables. Right now the whole map is just too clumped together.
3 Tert Count: I agree with one of the other posters, too many small counties in the light blue region. Remember, troop counts and region names have to go on these. To decrease the number of terts I would also say to clump all of the purple counties into 1 or 2 terts and merge that bonus with some of the Brown terts as 1 bigger Tidewater Region Bonus. There are around 100 (I think 90something) counties in Virginia. I don't think a map like this should have more than like 50-60 (this is just my opinion). So you're gonna have a lot of merging to do if you take it down that far.
4 Peninsula: obviously you need to figure out where you're gonna connect the peninsula terts, I don't like the idea of having the water as a tert, but that's up to you. I think you should just have lines connecting them like classic, or many other maps.
Regions (not all are great names, but I figured I'd try to think of a list to start):
Yellow: Shenandoah
Dark Red: NoVA (Northern Virginia)
Blue: Chesapeake
Purple/part of Brown: Tidewater
Green: Eastern Shore
Light Red: Plateau
Orange: Blue Ridge? - I would get rid of this also, merge w/ Red, Yellow, White
Light Green: Northern Piedmont/Blue Ridge/Central VA
Whitish: (Southern) Piedmont