An indicator device for alerting the driver of a pickup truck to the orientation of the tailgate includes a housing assembly and an indicator assembly carried by and extending from the housing assembly. The housing assembly is attached to the tailgate of the pickup truck in a position that causes at least a portion of the indicator assembly to extend from the side of the truck so that the driver can see the extending portion in the side view mirror of the truck. Viewing the position of the indicator assembly allows the driver of the truck to ascertain the position of the tailgate.