Landsat satellite data, acquired and processed by the U.S. Geological Survey, illustrate the rapid growth in the San Antonio, Texas region. San Antonio has grown to be the 7th largest city in the nation, with a current population of approximately 1.4 million. In 1991 when the June 16 image was acquired, the population was approximately 790,000. In the past 20 years it has been the 4th fastest growing city in the United States.
Unlike most large cities in the United States, San Antonio is not completely surrounded by independent suburban cities, and under Texas law it exercises extraterritorial jurisdiction (ETJ) over much of the surrounding unincorporated land, including directing growth and zoning. It pursues an aggressive annexation policy and opposes the creation of other municipalities within its ETJ. The restrictions on development by independent communities have allowed the city to control growth direction and have preserved useful agricultural production areas. Another factor in the growth formula has been the series of military bases and military airfields which ring the larger community.