Ask Washington Statewhat they require for you to get it. If you qualify to get it. Find out how much it is. If you have to file something at the courthouse to get that property find out how much it costs to do what you have to do and then make a decision as to whether it's worth it to claim the property.
The contents of this answer should be considered friendly advice, not legal advice and the answer should not be construed to constitute an attorney-client relationship.
You have not given enough facts to get a complete answer. If he died in FL, you might be able to get a summary administration completed. You need an attorney in a probate matter in FL.
R. Jason de Groot, Esq. We do not have an attorney-client relationship. I am not your lawyer. The statements I make do not constitute legal advice. Any statements made by me are based upon the limited facts you have presented, and under the premise that you will consult with a local attorney. This is not an attempt to solicit business. This disclaimer is in addition to any disclaimers that this website has made. I am only licensed in Florida.