Deductive inference is applied to choreograph the cooperation of multiple knowledge sources to respond to geospatial queries. When no one source can provide an answer, the response may be deduced from pieces of the answer provided by many sources. Examples of sources include • The Alexandria Digital Library Gazetteer, a repository that gives the locations for almost six million place names, • The Cia World Factbook, an online almanac with basic information about more then 200 countries. • The SRI TerraVision 3D Terrain Visualization System, which displays a flight-simulator-like interactive display of geographic data held in a database, • The NASA GDACC WebGIS client for searching satellite and other geographic data available through OpenGIS Consortium (OGC) Web Map Servers, and