Greenbrier State Park is one of the Maryland parks in thicket's catalog. thicket is a field guide to the parks near you: it maps the ones you have never noticed, gives you a reason to actually go, and keeps a record of where you have been.
Where it is
Greenbrier State Park is in Washington County, Maryland. Its approximate coordinates are 39.53679, -77.62202.
Check in at Greenbrier State Park
thicket verifies you are actually here by GPS when you check in, so a visit means you went. Checking in builds a streak, earns achievements, and fills in your map of the places you have been.