It is not likely that the swans are Trumpeter swans as they are not usually found that far east of the Mississippi River region although this point is misrepresented by federal and state wildlife officials.
If the swans have a small yellow patch near the eye and bill area called the lore, they are possibly Tundra Swans as these swans have black bills.
If the swans have an orange bill, then they are Mute Swans. Now, having said this, if the swans are young juveniles that recently turned white, but their bills look black, they still could be Mute Swans.
Swans and other waterfowl will rest along the migratory path and rest in what are known as stopovers. However, there would be many more swans if this was a true stopover, so this may be a temporary resting area. If these are young birds, they may not know where else they are to go if they were separated by older adult swans or if they are parents with a younger bird, they may be allowing it to rest.
The best thing that can be done is to quietly call around to wildlife rehabilitation centers to see if they know anything about swans, especially Mute Swans. If they tell you they do not have any knowledge, tell you that you should contact your state wildlife authorities or that they will take the swans and have to kill them, then you know why we are saying to quietly ask around.
State and wildlife officials will kill entire families or flocks of Mute Swans so that the species can be eradicated in the U.S. The purpose is to free up wetland habitats so that the larger Trumpeter Swans can be introduced for Trophy Waterfowl hunting purposes.
If the swans have not left by tomorrow, we would suggest to quietly ask if someone might help. The Regal Swan