Wow, I think this is a new exhibit. Do you remember where on the grounds it is? (If it is between the bighorns and Village Watutu, then it is a former antelope exhibit being used for pronghorns. But if it is between the bighorns and Eagle Canyon, as I suspect, then it is a new exhibit.)
It is a brand new exhibit, and it is between the bighorns and Eagle Canyon. The peninsular pronghorns are just above the even newer Monarch of the Desert habitat (jaguar) on the zoo map.