A user-friendly, interactive World Wide Web system was developed to access and analyze health data that is stored in an Oracle relational database management system (RDBMS). This allows a user to query the database through the Internet using Structured Query Language (SQL). The combination of an easy interactive data retrieval system and GIS tools provides powerful methods to organize, visualize, and manipulate data through construction of simple to complex queries. This integrated system was created by the Blackland Research Center and is called the health information system (HIS).