An event processing system for distributing geospatial computations with geo-fences is disclosed. The system can partition and distribute geo-fences efficiently for parallel computation, and can track a potentially unlimited number of moving objects. A computing device determines a minimum bounding rectangle (MBR) covering a geographic area indexed by a geo-grid, and partitions the MBR and a set of geo-fences to a plurality of processing nodes. The computing device receives input events of a stream comprising locations within the geographic area. The device distributes the events to partitions on processing nodes, based at least on the events' locations. The device can determine a partition identifier corresponding to a respective location in constant time. The computing device then combines partition results to obtain a single geospatial computation result.