It is free if you are a resident of Fairfax Country. If you are not a resident, there is a $10 entrance fee on weekends and holidays.
$10/vehicle fee only required for non-Fairfax county residents on weekends and holidays from April - October!
I'm a Stafford County resident and they let me in without a fee, when I show them my license.
It is free for Fairfax county residents. It is also free for everyone weekdays, or winter months. During spring/ summer on weekends or holidays, it is $10.
Non county residents $10 on weekends.
Fairfax county residents have free access to the park
When we were there there was no entry fee.
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