Any trails in northern Virginia? (Near Ashburn preferably)

my friends and I all got Coleman mini bikes a few months ago but we’re having a really hard time finding public trails to ride in. We kinda just want a place where off road vehicles can ride for a few miles but I can’t seem to find anything. I live in ashburn and there are tons of mountains less than 15 minutes from me and I find it weird that there aren’t any trails anywhere within an hour and a half. If anyone knows anywhere I can ride I would appreciate it a ton. Thanks!
 
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