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1. Arizona’s native fish species are among the most imperilled fauna in North America. Knowing the current distribution of native fish and their habitat is critical to their management and conservation, but the last detailed mapping effort was more than 30 years ago and pre-dated computer mapping techniques.

2. Current distribution of 34 native fish species was modelled by identifying perennial stream segments for which species presence had been documented. A composite of these single-species maps displays a pattern of species richness that can inform conservation, especially when overlaid with maps of management status or invasive species.

3. The map overlays suggest that conservation priorities should include Eagle Creek, the Verde River and its tributaries, Aravaipa Canyon, the Virgin River and Black Draw, which together hold 63% of native fish species. Of the 32 streams that support five or more native species, 28 have at least one non-native fish species, indicating that a more aggressive programme of removing non-natives may be critical to maintaining those native populations.

4. The U.S. Forest Service and Native American tribes administer the majority of occupied stream habitat (30% and 27%, respectively). While private lands hold the third-highest amount of occupied habitat (19%), they control streams occupied by the greatest total number of native species (30). Conservationists should work more with private land owners, while also coordinating efforts with the U.S. Forest Service and North American tribes.

5. These data are publicly available (on the Internet, URL: www.azconservation.org) to encourage refinement and use. Copyright (c) 2001 John Wiley &, Sons, Ltd.