Examination of the factors contributing to the development of the Austin/San Antonio corridor as a high-technology center in the years 1945-1986. The paper uses a conceptual framework called the Technopolis Wheel, which identifies seven segments as fundamental in regional high-tech growth: university, large and small technology companies, state-local-and federal government, and support groups (e.g. chambers of commerce). The major contribution of the paper is its emphasis on using multiple data sources to measure the relative importance of these segments. It concludes with case studies of Microelectronics and Computer Technology Corporation (MCC) in Austin and the biotechnology sector in San Antonio.