Given the great amounts of data being transmitted between devices in the 21st century, existing channels of wireless communication are getting congested. In the wireless space, the focus up to now has been on the microwave frequency range. An alternative for highspeed medium- and long-range communication is the millimeter wave spectrum, which is most effectively used through point-topoint links. In this paper, we develop and compare methods for verifying the Line of Sight (LOS) constraint between two points in a city. To be useful for online wireless network planning systems, the methods must be able to process terabytes of 3D city geolocation data and provide answers in milliseconds. We evaluate our methods using data for the city of San José, a major metropolitan area in Silicon Valley, California. Our results indicate that our Hierarchical Polygon Aggregation (HPA) method is able to achieve millisecondlevel query times with very little loss of precision.