USAFAcol, you're right that typical ghost-town books and websites, are usually no good for our purposes. They tend to focus on the touristy places. Or .... *obvious* places. And any such obvious coffee-table type books are for RV people (eg.: Sunset home and garden ghost towns of the West" type books). And so they've either been pounded to death by other md'rs, or are a nightmare of trash and target shooting (bullet shells, campfire junk, etc...) all over. Or they're just modern glitzed up tourist attractions (Tombstone, etc....)
A buddy and I had several such books with us, and took off through So. CA, AZ, and NM years ago. Within a few stops, we figured the books (even though decked out with mouthwatering pix sometimes) were of no use. The mere fact of "being no secret" didn't help. So we wised up and went into various museums we came to, small town libraries and started sluething for obscure books, articles, etc... And if we found something interesting (stage stop citations, emigrant camp spot names/locations, etc....), we would then cross-reference to see if they were well-documented and in the coffee-table type books. If they weren't, and we found scant few other references, THEN we would go hit them. We started finding old stuff then
And don't be thinking you're necessarily looking for "bodie type" ghost towns. Eg.: still standing spaghetti western type ruins. On the contrary: locations of past watering holes, stage stops, fort sites, emigrant camp sites, etc... can be nothing but a naked cross-roads, with nothing visible to indicate anything was ever there. Hence the "coffee table" type books tend to focus on the ones that have some sort of ruins still visible. While a mere emigrant camp spot is not interesting enough to be in such books, if nothing is there to see.
Also we did good just driving the back-roads of old routes that link 2 old cities. And we'd look for any out of place fruit trees, chimney, foundation, or any other such indications of where a habitation or stop spot had been.