Ridgeton doesn't seem to exist anymore. At any rate, we couldn't find it, except for a single sign near the railroad track. We crossed over that track three or four times, driving along those country roads and trying to find any other trace of it. Alas, we had no success.
It seems that Ridgeton is another example of a town that once existed because of the railroads, but slowly petered out of existence, one family at a time. The big difference is that many other such towns have grain elevators, so at least some physical reminder remains.
I did find a web site that mentions the railroad location, as well as this YouTube video showing the actual train journey between Melvern and Ridgeton.
Much to our amusement, the roads here are laid out much as they are in Topeka, complete with the same names. It was funny to be driving around looking for a ghost town somewhere between Wanamaker and Urish.
One thing we did come away with was an extremely filthy van. The rains of the past few days had left the dirt roads pretty muddy in places.