I got back from surveying it.  The gate is indeed locked with a 4 digit code.  The front of the gate sign says "Road Closed - Authorized Vehicles Only".  It does feels like the sign is on the wrong side cause the rode is not closed on the other side.

Another gate just North of to it has a sign nearby that says "Wetland Mitigation Site".  I suspect what happened is the that the surrounding industrial companies were dumping near a protected wetlands, so they closed the road and added a gate and camera.

They also have painted lane lines on both sides of the gate / turning circle

Because it is locked, I think the best compromise is to bump it down to a tertiary, which I have done.