Methods and apparatus are disclosed for estimating, based on data collected from multiple types of data sources, the locations of cell towers. An example computer implemented method for estimating locations of cell towers includes identifying, with the processor, estimated locations for respective ones of the cell towers based on data collected from a higher-ranking data source; when estimated locations for respective ones of the cell towers have not already been identified based on data collected from the higher-ranking data source, identifying, with the processor, estimated locations for respective ones of the cell towers based on data collected from a lower-ranking data source; and communicating the identified locations for the respective ones of the cell towers.