Scenario design in the back of my head

While working on my current projects, I've been thinking about a future challenge -- specifically, that of combining a location-based exploration scenario with the type of scenario I naturally gravitate toward running, which is the Call of Cthulhu-style mystery.

This relates not only to the Call of Cthulhu stuff I'm working on at the moment, but also to something I've been turning over in my mind for a year or so -- the possibility of writing up a scenario I ran in my D&D game and putting it out there in some kind of published form. "The Magonium Mine Murders" is sort of a murder-mystery sandbox set around a mining community in which a high-profile murder has just taken place. But there's bandits and something strange going on in the woods, there's a crooked fight promoter, there's strange goings-on in the mine ... it's not a linear mystery, or at least it doesn't have to be: it's just an environment that has a lot of shenanigans going on it. Think the usual location-based scenario except that maybe instead of having a 3:1 fight:shenanigan ratio it's the other way around. 

This kind of thing is usually portrayed with a long list of NPCs, but I'm not sure that's the best way to do it. I think the ideal way to do it would be to combine an old White-Wolf-style relationship map with an actual map. It'd have to be on the central two-page spread of the scenario, but I think it might work. I may try to rough out some kind of example, although I am no kind of artist or cartographer.