1. In a device of the character described, means for locking a movable object such as a trailer, camper or the like to the ground, said means comprising a conventional trailer tongue securely attached to the object, said tongue being of the type having socket means for lockingly receiving a ball member, and further having locking means movable to permit release of the ball member from the socket means, the invention comprising a rigid stake having a pointed and threaded lower end whereby said stake may be securedly screwed into the ground, said stake further having a ball member secured thereto adjacent its upper end, said ball member being adapted to be lockingly received by said trailer tongue, and link means interconnecting said stake and said trailer tongue so as to prevent said stake from being turned sufficiently to become unscrewed from the ground.