There are currently no THPOs in 18 states. Although there are no THPOs located in those states, it is considered ancestral territory for one or more Tribes. State Historic Preservation Officers (SHPOs) typically maintain contact lists for Tribes with ancestral territory in their state, including those without a THPO. Links for those SHPOs are located at the bottom of the page. Additionally, links to all SHPOs can be found at the NCSHPO website.