A re- inventory of state forests in West Virginia was initiated during the winter of 2002. In order to facilitate resources data collection and processing, a computer- based timber cruising system was developed based on objected- oriented modeling techniques. The system consists of three components- handheld data collection system, data transfer, and data analysis all of which were developed as stand- alone objects. The handheld system, which is Windows CE based, was used to collected over story and understory tree data in the field. All components were successfully tested and used in the large- scale inventory of West Virginia’s state forests, and could be adapted for use in related forest inventory projects.