Three mares are missing on Assateague Island.
The National Park Service says it is believe they have died.
The Salisbury Daily Times reports that word of their disappearance came in a survey of the population of wild horses on the island.
One was identified as Bessy Twister N6BK while the other two were identified as N6H and X24 Patty.
The census found there are a total of 76 horses.
They breakdown to 21 stallions and 55 mares.
