Now, in addition to the facilities at the northern/Maryland end of Assateague Island - the national seashore and the state park, there is camping available on the southern/Virginia end. There are some campgrounds in the town of Chincoteague, the companion island to Assateague, and next door to the town is the Chincoteague National Wildlife Refuge, which is an outstanding place for viewing wildlife of all types thanks to a nice combination of freshwater impoundment, forest, and saltwater stuff.
About the ponies v horses question, I stick with the letter of the law on horse size. Under 14.2 hands = pony, over = horse, no matter the breed. So I always argue with signage that refers to these little things as horses. The signs never fight back, though.
Photos you say?
From the north end:
A white-tailed fawn
From the wildlife refuge:
the endangered (due to deforestation) Delmarva fox squirrel
river otter in the freshwater impoundment
willets on the beach
The sika are pretty cute. They ended up there because an irresponsible boy scout troop at the turn of the 20th century turned their petting zoo occupants loose on the island. Now they're a managed herd, but subject to some hunting unlike the ponies.