Richard,
I live in Northwest Oregon also, and have been trying to keep a female (recent mommy!) Rubber Boa.
She is full grown and just had 5 babies.
She has now escaped for the second time. First time I found her within the hour hiding nearby.
This time I put her in her feeding box and next morning- no snake!
In your experience would she go far, in a crack or crevice nearby or keep traveling?
Help!