Originally Posted by
BThumme
As mentioned above, at least for me, what I find the most helpful is going to an airports wiki page and looking at "Airlines and Destinations."
Alternatively you can go to google.com/flights and filter an airport by united nonstops only and see that way, but keep in mind some flights aren't everyday/are seasonal.
Forgot about the second option. That sounds like the best for me.
I really don't understand what UA was thinking. How hard is it to have a simple route map available.