Usually always rooms available at Dover. Call the front desk for availability.
I always find it's better to call the lodging office and check. Dover ususlly has rooms, but a reservation is good to have. I recently stayed at Wright-Patt and the DOD Lodging site said non avsilable, called direct and got two rooms.
You can check here: http://af.dodlodging.net/propertys/Dover-AFB
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