geterdun,

I would get there early and use a locater call before daylight (owl hooter) and hope to hear some gobbles. If you do cover ground and setup close to them. If that scenario doesnt work or if you dont hear any gobbles, then you must do hunting/scouting at the same time. Call aggresively or use a locator call while you quietly scout the property, hoping to hear a shock gobble or spot with your binos. If you come to an area with turkey sign, i.e droppings, tracks, feathers, or struts marks then decide if you want to setup or keep walking. Be prepared to spot strutters in the fields before they spot you.
I have employed this tactic many times and have been very successful.
If possible try to get a map of the state park while you are there, that would help. GOOD LUCK and BE SAFE!!