The measure amends the California Constitution to prohibit any gambling compact that would allow a tribal casino located in an “urban area.” The measure defines urban area to mean all land within 15 miles of an area determined by the 2000 U.S. Census to be an “urbanized area” (generally having a population of at least 50,000 people). The measure would not apply to any land of a tribe that, as of January 1, 2005, was eligible for gambling (by means of an existing compact).