Wikipedia:Reliability of GNIS data/Cleanup methodology and resources
Books to check against
There are usually Arcadia Publishing books for a particular locality. Arcadia books are not the be-all-and-end-all, but they do point the way and are generally the results of local historians already having done for us the poring over old maps, records, and photographs. Arcadia (and other local history) books helped sort out Robert, California (AfD discussion) and Escalle, Larkspur, California; helped identify what Salminas Resort, California (AfD discussion) actually was; and conversely made the cases stronger against the likes of Ettawa Springs, California (AfD discussion). All of these were two-sentence GNIS-only stubs at the time of deletion nomination, all claiming "unincorporated community".
- Gazetteers
- These are useful for telling whether an "unincorporated community" that is just a dot nowadays is a historical post-town/post-village or only a post office; that then might be found in local county/state histories. Lippincott's, in particular, has a uniform scheme for this. Take care about dates, of course.
- Baldwin, Thomas; Thomas, Joseph (1855). Lippincott's pronouncing gazetteer. Philadelphia: J.B. Lippincott. hdl:loc.gdc/gdclccn.tmp96023479. LCCN tmp96023479.
- Lippincott's gazetteer of the world. Philadelphia: J. B. Lippincott & co. 1880. hdl:loc.gdc/scd0001.00193145826. LCCN 02002832. OL 24447594M. (Lippincott's gazetteer of the world at the Internet Archive)
- Books of place names
- In many states people took it upon themselves to identify the origins of the names of places within the state. These vary in quality but have often helped to clarify matters by giving a more specific characterization of the places in question. We have found these used as GNIS sources, often quite badly.
- Old local histories
- As with the place names books, quality is variable, and those from around 1900 tend to be a bit gushing in their praises of the forefathers and heavy on the anecdotes. That said, their age (typically with a few decades of the foundation of the places, at least outside the east coast) and attention to detail can help resolve matters.