Way Shorter approach, camping at the trailhead, and easily as good or better climbing than El Cajon.
I think a destination area needs convenient camping, or lodging close by.
I agree with the poster who noted that SD County in general is a worthy climbing destination. You have Woodson on your OP list, and it's killer for what it is, plus it's got history, but the total of SD climbing makes Woodson look minor. Lots of SDs climbing is so new that the climbing masses haven't caught on to what's up
There are a couple of other sites in New Mexico:
The biggest area is the Sandia Mountains near Albuquerque. There are several excellent granite climbs there.
Another is Los Brazos Cliffs in Rio Arriba County. I use to climb with the Los Alamos Mountain club on the private land. It is a big Quartzite climbing area. The rock is solid.
The last site is Questa Dome near Taos.
Having seen several of your excellent map-works, in magazine pieces and daily on my office wall (dreaming of Horseshoe), I imagine that within the larger-named areas (Sierras, Adirondacks) you might include a few noted peaks, walls or concentrations?
I especially appreciate your considering great-but-less-spectacular areas that are easy to fit into a road trip. I am proud to see Quartz Mt, OK on the list, and Mt Magazine; these are both great areas that would enrich a cross-country trip with both beauty and some old-school runout adrenaline!
That said, I would second the inclusion of Sedona towers, as, like those above, it is unique and easily accessed from I-40. My favorite trips have followed a drive-a-day, climb-a-day-or-two pattern.
I would also second Seneca Rocks, WV for its uniqueness, history and geography. Not so easy to get to but evena rock-starved visitor to DC could make a long day trip to the 'wall of a thousand pItons' and sandbagged trad fun on whIte rock lIke I haven't seen elsewheret. On the other hand Ragged Mountain CT would only belong if you felt compelled to include something from every state - it's about the size of Lower Mt Scott in the Wichitas, or maybe the Confederate Cracks at the 'Shoe. Fun but far from a destination for any but starved locals.
Assuming the '100' number is a general idea rather than hard and fast. Artistic License.
Look forward to it especially as I am about to move to NH and will be exploring that side of things. Hope never to miss a Hell, though, as the Creed always keeps me stoked for another year.
Let me first say I think this is a great idea, especially if it stays more on the art side. That being said having pertiment, accurate information is always good too. My only significant critique would be to make sure to add Lovers Leap for the lake Tahoe area, just too special of a place with too much history to be left out, in my opinion.