I don't know about Oregon, but I am a social worker in IN, and here we try to get a family member to adopt before foster care is sought. The exceptions would be if you were somehow considered unfit or a part of the problem. The other case would be if your grandchild was in need of what we call a "treatment" foster home. This is a court ordered placemenmt with a family who is trained to help the child deal with issues, such as abuse or psychological disorders, such as depression or bipolar.
If your grandchild is basically healthy, and you are an upstanding citizen, then you should have the child, and you have rights and options. Can you give me more info?? I'll try to help.
Jess