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The design of updatable heterogeneous geographic databases is a challenging problem. A first version of a land cover database was built to store heterogeneous information concerning agricultural, forest and other cover types from different sources for the state of Mexico. Remotely sensed data came from a single type of pre-processed optical image. Digital official maps and statistical information were also included. This non-updatable database is queried interactively through a specially built application. The database is also being used to generate and distribute map atlases to state government agencies and to different kinds of users. Land covers change rapidly in this geographic area, so the database is expected to be updatable in future versions. In addition, advanced users demand query facilities for decision support and more accurate data derived from other types of satellite sensors. The original database design is not useful anymore. We describe here the new object based design approach towards building an updatable geographical database. Considerations for accomplishing this task range from user characterization and data organization aspects, to providing consistent information. The conceptual framework is the object data model described in this work. Implementation of the main update and query functionalities utilizes MapObjects.