Answer: This sounds like an episode from a Jerry Springer reality show! Your question doesn'tmake it clear whether the estate was formally filed for probate in court, in which case this "Administrator" would be subject to court supervision and would have to have a bond. I'm suspecting that is not the case - but if it is, you may want to secure legal counsel to notify the court of what's happening and perhaps get him removed.
Assuming that the person is just a designee for the un-probated estate (I will call him the "representative"), I would suggest that you look to ORS 90.675(20), which applies when a resident living alone passes away. Subsection (20) is summarized below, but should not be used as a substitute for reading ORS 90.675 (linked here) in its entirety:
- This subsection (20) applies the same duties as those of a resident who abandoned the property.
- It also applies to any personal representative named in a will or appointed by a court, or any person designated in writing by the decedent to be contacted by the landlord in the event of the tenant's death;
- The 45-day abandonment notice required in ORS 90.675(3) (go to above link) is to be sent by first class mail to this representative at the premises, and also personally delivered or sent by first class mail to them if actually known to the landlord.
- If the representative responds by actual notice to a landlord within the 45-day period provided in the letter and so requests, the landlord shall enter into a written storage agreement with the representative or person providing that the personal property may not be sold or disposed of by the landlord for up to 90 days or until conclusion of any probate proceedings, whichever is later.
- Note: Entering into the storage agreement includes the duty to pay a "storage fee" which can be no higher than the space rent. This duty is not triggered until the 45-day letter is sent. Presumably you will use a good storage agreement that requires, among other things, compliance with all applicable park rules and state, federal and local laws and ordinances, including a duty to maintain the space. On- site destruction of the home is NOT maintaining the space. Depending upon the home's age, on site destruction could be a violation of certain environmental laws, due to potentially hazardous material used in construction. In fact, since there is a risk that the representative will not comply with the storage agreement - based on his threat of destruction - you may want to consider - only upon the advice of your attorney - to restrict his unsupervised access to the home. Destruction of the home would not only take it off the tax rolls in violation of Oregon property tax law, but it would prevent you, as the landlord, from selling the home upon failure of the representative to meet his obligations. Remember, in addition to the tax collector, you have a vested interest in seeing the home sold for recoupment any sums due (arguably including attorney fees) incurred during the abandonment process.
- Since the abandonment law requires that the landlord has a duty of safe keeping pending completion of the abandonment process, it is my belief that this entitles the landlord to secure the home (e.g. with a new lock) so that heirs and others cannot enter and remove personal property.
- A storage agreement entitles the representative to store the personal property on the space during the term of the agreement, but does not entitle anyone to occupy the personal property.
- If such an agreement is entered into, the landlord may not enter a similar agreement with a lienholder (if any) until the agreement with the representative ends.
- If the representative requests that a landlord enter into a storage agreement and there is a lienholder, also, you should review subsections (19)(c) to (e) and (g)(C) of ORS 90.675, which describes the rights and responsibilities of a lienholder with regard to the storage agreement.
- During the term of the Storage Agreement, the representative has the right to remove or sell the property, including a sale to a purchaser or a transfer to an heir who wishes to leave the property on the space and become a tenant. However, this prospective tenant is subject to the same statutory requirement, including landlord qualification and approval, as found in ORS 90.680 (linked here). The landlord also may condition approval for occupancy upon payment of all unpaid storage charges and maintenance costs.
- If the representative violates the storage agreement, the landlord may terminate it by giving at least 30 days' written notice to them stating facts sufficient to notify them of the reason for the termination. Unless the representative or person corrects the violation within the notice period, the Storage Agreement terminates as provided and the landlord may sell or dispose of the property without further notice to the representative.
- Upon the failure of a representative to enter into a storage agreement or upon termination of an agreement, unless the parties otherwise agree or the representative has sold or removed the home, the landlord may sell or dispose of it pursuant to sale provisions of ORS 90.675 without further notice to the representative.
So, in summary, the abandonment statute - which is quite lengthy and somewhat difficult to follow - applies in this case, and with proper guidance, you should be able to successfully deal with the representative.
 I'm not rendering a "legal opinion" in this Answer - PCQ