An inventory storage and retrieval system and method are provided for a shipping or storage facility. In an embodiment, the system includes: (a) a mobile computer and radio on a load-handing vehicle; (b) sensors on the vehicle to determine the ground location and orientation of the vehicle; (c) encoders that determine the position of a lifting mechanism relative to a chassis of the vehicle; and (d) a base computer and radio that communicates with the vehicle. The system maintains an inventory database of items and their respective storage locations in three dimensions as a result of the loading activity of the vehicle. The data can be used to guide the vehicle for ground movement generally to a storage location, appropriately orient the vehicle, and then to move the lifting mechanism of the vehicle to deposit or retrieve the item at a particular storage location.