How much is entry? (I know some State Parks charge by the car and/or each person)

I think it was $3. I remember putting $1 bill and a bunch of coins in the envelope. It is based on an honor system. As you enter the park, at the entrance, you will see a skinny metal short post on your left. Envelopes are provided.

I think it's 2 or 3 dollars per car

$2 for residents of MD. $4 for non-residents

Thank you, guys.