Guadalupe-Hidalgo Treaty Land Claims Act of 1999

Guadalupe-Hidalgo Treaty Land Claims Act of 1999 - Establishes the Guadalupe-Hidalgo Treaty Land Claims Commission to determine the validity of land claims arising out of the Treaty of Guadalupe-Hidalgo of 1848. Authorizes three or more eligible Mexican descendants in the State of New Mexico who are also descendants of the same community land grant to petition the Commission for such a determination on behalf of themselves and all other descendants.

Directs the Commission to establish a Community Land Grant Study Center at the Onate Center in Alcalde, New Mexico, to be responsible for directing the research, study, and investigations necessary to assist the Commission in performing its duties.

Authorizes appropriations.