While most folks in North American are familiar with the Common Raccoon (Procyon lotor), few ever get to know their cousins the coatis. The name coati refers to a number of species in two genera: Nasua (coatis; 3 species) and Nasuella (mountain coatis; 1+ species). They are members of the Racoon family Procyonidae comprised by the Raccoons (3 species), Ringtail & Cacomistle, Olingos, and the Kinkajou. Like all members of this family, the coatis are native only to the Americas.
In the U.S., you could possibly find the northern most coati (Nasua) species -- the White-Nosed Coati (Nasua narica) -- which occurs from south eastern Arizona down to northern South America. The other two species occur on the island of Cozumel and in South America, respectively. The mountain coatis (Nasuella) occur in northern South America.
Here's a South American Coati (Nasua nasua) photographed at the Denver Zoo when I last visited there in July, 2009. This widespread omnivorous species includes over a dozen subspecies.
For more info and pictures of Procyonids, visit the University of Michigan's Animal Diversity Web: Family Procyonidae.