This is a real sign.
From another forum:
This is in Norton, Vermont , on the U.S. - Canada border, at the intersection of Vermont highways 114 and 147.
It was put up at the request of the U.S. Border Patrol.
There have been multiple accounts created with the sole purpose of posting advertisement posts or replies containing unsolicited advertising.
Accounts which solely post advertisements, or persistently post them may be terminated.
From another forum:
This is in Norton, Vermont , on the U.S. - Canada border, at the intersection of Vermont highways 114 and 147.
It was put up at the request of the U.S. Border Patrol.