Dog abandoned at apartment complex dog park.

Someone either abandoned their dog or put a stray in my apartments complex, and I was wondering if anyone new a good organization to call or inform? If we call animal control it will most likely end up in a shelter so I’d like to call someone else if possible. I believe the dog was abandoned because he’s super friendly and there’s no other way I can see a stray dog getting into the complexes park. If I had to guess I’d say this dog isn’t older than a year and it’s a German Shepard mixed with something.