Search the web for specific tribes and ask them if they need a volunteer.Some sites to start with are:
http://www.nativeculturelinks.com/nations.html
www.hopi.nsn.uswww.newmexico.org/culture/pueblos.html
Oglala Lakota Sioux
Cherokee Links
CHEYENNE (shy-EN
Sac and Fox Nation - Oklahoma
Volunteering in Indian Country
http://www.ipsl.org/programs/lakotanationvolunteer.aspx
http://www.nativephilanthropy.org:2015/accomplishments.html
www.hoopavalleytribe.com
Blue Feather Alliance:Help Pine Ridge
Adopt And Elder !!!
www.kstrom.net/isk/maps/or/ormap.html
http://sipapu.gsu.edu/html/kiva.html
For those interested in education: www.oiep.bia.edu
http://operationmorningstar.org/