There is parking near the mansion which is where Google Maps will take you, but you can also follow signs to any of the picnic areas and there is parking at each of them.
Depending where you are located you can get there off of providence rd. Which goes off rt 252. Or you can drive up rt 352 to Gradyville rd and follow that to the park.
When you enter the location into Google Maps it will ask you which part you want to go to. I parked at Ridley Creek State Parque and there was parking right where Google Maps directed me. The signs should also indicate parking if I recall.
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