The Census Bureau has created data tables showing counts and percentages of persons by tribe. These tables show data for American Indian and Alaska Natives "alone" and "in combination with one or more races". When data are shown for the "alone" population it represents persons who indicated they were only American Indian or Alaska Native. When data are shown for the "in combination" population it represents all persons indicating they were American Indian or Alaska Native and one or more of five other major races.
The same is true for tribal identification. When data are labled as one tribe "alone" it represents all persons indicating only one tribe on their census questionnaire. Alternatively, there were counts of persons that indicated two or more tribes.
The tables linked below are posted on this web site in Microsoft Excel format only. For these same data tables in PDF and text format go to the Census Bureau's web site at http://www.census.gov/population/www/cen2000/phc-t18.html. There you will find data for other states, for the U.S. as a whole, and for regions and divisions within the country. You may also be interested in the 12-page Census 2000 Brief called "The American Indian and Alaska Native Population, 2000" located at http://www.census.gov/prod/2002pubs/c2kbr01-15.pdf.