I would no longer camp there if ticks were such a problem. There may be legitimate reasons for the owners/agency not spraying the area that you are unaware of. By spraying yourself, you can unintentially do a lot more harm than the little bit of good for your short stay.
I would contact the owner/agency and let them know that the ticks have gotten out of control and therefore you will no longer be staying there. They can then determine whether spraying is a viable choice or not.
In the end, it's not my property to with as I wish. If I don't like how it is, I can choose to go elsewhere.
