An apparatus and method for monitoring and reporting the status of a mobile asset are described, where the mobile asset may be moved by a transport vehicle from a starting location to a destination location. The method includes providing destination information to a tracking device on the mobile asset, and setting a boundary about the destination location which is also referred to herein as a geoboundary. As the mobile asset moves from the starting location to the destination location, the current location of the mobile asset is determined, and a determination is made whether the current location is within the geoboundary. If the current location of the mobile asset is within the geoboundary, an arrival message is transmitted from the tracking device. Preferred embodiments of the invention include the step of transmitting a departure message from the tracking device if the current location of the mobile asset moves from within the geoboundary to outside the geoboundary. The tracking device apparatus preferably includes a tether sensor and one or more door sensors. The tether sensor senses whether the mobile asset is electrically connected to or disconnected from the transport vehicle, and the one or more door sensors sense whether one or more doors on the mobile asset are open or closed. The apparatus includes a processor, a location determining device for determining the geographic location of the mobile asset, and a transceiver for transmitting and receiving status messages related to the status of the mobile asset.