Illustrator join problem

ARGH!

So I exported an outline of Washington state out of a mapping program to an AI file. For some weird reason it always sends complicated outlines in pieces, so I have to spend an hour or so going in and joining all the pieces together. This was going very well until all of a sudden, for no reason that I can see, I am getting the error message:

“Can’t join the points. Can’t add an anchor-point”

WTF? If I clip the line further down and then join the original two points then it works?? But now can’t join where I cut. I need to give this poly a fill and can’t unless it is all joined. There are two places where it is giving me this error message.

What can I do?

:hair: