This report outlines a planning approach taken by a Federal Government partnership that is meant to promote sustainable development in the future, integrating both sides of the United States-Mexican border. The twin-city area of Nogales, Ariz., and Nogales, Sonora, Mexico, known collectively as Ambos (both) Nogales, has a common borderland history of urban growth presumably based on changes in policy and economic incentives. We document changes over time in an attempt to identify colonia development and settlement patterns along the border, combining a community-participation approach with a remote-sensing analysis, to create an online mapping service.