What an unpleasant situation. More than worried about HER, if i were in your situation, I'd also be worried about me and my neighborhood. yes, there is the danger of fire. but where is she going to the bathroom?? how is she disposing of her trash?

there is more to it than "if she is living on her own land" because her land is attached to YOUR land. and what she does affects the entire community.

i'm just trying to think about who i would call. i really don't know. i would probably start by looking at the "city of portland" section of the phone book. if i found nothing, i'd call the non-emergency number for the police and ask them what to do. at least they might know how to direct the call.