The Madrean Archipelago, or Sky Island, region of the southwestern United States and northern Mexico is recognized for its great biological diversity and natural beauty. This conference brought together scientists, managers, and other interested parties to share their knowledge about the region and to identify needs and possible solutions for existing and emerging problems. It provided a forum to update the state-of-knowledge acquired since the first conference in 1994. The proceedings contains over 100 articles and additional abstracts from the plenary sessions and from concurrent sessions covering biogeography, ecosystem monitoring, science-based management, cultural resources/history, invasive species, hydrology and biodiversity, conservation planning, ecology, fire, conservation practice, and global climatic change. Abstracts in Spanish are included. The summary of an open forum at the end of the conference provides additional thoughts about current and future needs for the Madrean Archipelago.