I don't remember where I read it , but the "distance" is variable depending on how far you typically go to find a cache. For instance, if most of your caches are within a 25 mile radius from your home coordinates, then another state would be out of the question. However, if you frequently find caches several hundred miles from your home coordinates then it may be acceptable. Ultimately it will be up to the approver's discretion as to whether he/she believes you will be able to adequately maintain it.