I received a check in the mail for $4720 from a PLAINS SERVICE INC. Is this real or a scam?

...(in partnership with fidelity international). They are claiming that I won a contest and will receive $250000 from a total prize award of $87 million. I must cash the check given to pay the applicable tax of $2,970. The fees are payable via a tax agent at all western unions/money gram locations. I must advise my claim agent before I attempt to use the check. Is this real or a scam?