American FactFinder is the Census Bureau’s gateway to accessing population, housing, and demographic statistical data resulting from Census 2010, Census 2000 and the American Community Survey.
The American Indian and Alaska Native data and links webpage offers dozens of additional links to information and news about Census Bureau programs and statistical data available specifically for tribes and tribal geographies.
A list of federally recognized tribes can be found in the Federal Register notice included with the current Tribal Leaders Directory [PDF].