Check your local animal care ordinances re permissible chain weight. The size of that thick, heavy chain might be illegal, depending in where you are (too heavy). A call to animal control might conceivably spring her from that life...and into your arms when she becomes adoptable at the shelter.
I know of at least one state that allows prosecution for too-heavy chains under cruelty laws (since the weight can severely damage the neck and spine). I don't think most will, though.
This is not a local deal. She's 350 miles away. I am going down there Wednesday. I just would like to peacefully go get her. I don't even have an address. Most likely rural... and getting help for an animal in a rural location is nxt to impossible. I observed a starving horse once... I made literally HUNDREDS of phone calls. Every one of them said it's not their job. Finally talked personally to a local sheriff deputy who ended up actually getting on it, the person had everyone convinced the horse was just "old".
I am only one, but I am one. I cannot do everything, but I can do something. And I will not let what I cannot do interfere with what I can do.
- Edward Everett Hale