Anthony,
There are not APA or BJC "sections". The site will return everything within a radius of an airport, or you can search for stuff along a flight route. You specifiy what you are interested in (restaurants, museums, etc), and how many miles you are willing to fly.
In your example it looks like one of our members loaded a bunch of stuff around BJC. If you know of some stuff around APA you can submit that. Bill or I will review the submissions to make sure it's a somewhat airport-centric destination, then it's approved and made available for everyone to search. I also monitor the feedback (no approval process though), if one of our destinations goes out of business I remove it from the database. So what we have here is a community maintained database of flying destinations. So far the model is working great - we've had more pilots join and more destinations loaded in the last few weeks (we "opened our doors" late Sept) than I could have imagined.
Did this answer your question?
-Walter