A major research topic in geographic databases is that of interoperability, i.e., the capability to access transparently remote data and processes in an open environment. This paper addresses the issue of information modeling for interoperating geographic databases. In particular, it deals with the topic of exchanging semantics at the information systems context. Our proposal is based on the peculiarities of spatial data, namely field- and object-based views of space and spatial relationships, that are critical for the representation of information in an interoperable environment. A generic Geographic Data Model that encapsulates these semantics and makes their interchange among remote systems possible and without ambiguities, is proposed. We show with an example how this model supports interaction among heterogeneous spatial application domains. This research effort is based on (a) the requirements expressed by the OpenGIS community, (b) results from modeling “classical” interoperable applications, and (c) a well-established theory on database modeling of geographic applications.