Guadalupe-Hidalgo Treaty Land Claims Equity Act of 1998

Guadalupe-Hidalgo Treaty Land Claims Equity Act of 1998 - Establishes the Guadalupe-Hidalgo Treaty Land Claims Commission to determine the validity of certain land claims arising out of the Treaty of Guadalupe-Hidalgo in 1848. Authorizes the Secretary of State to negotiate bilateral agreements with the governments of Mexico and Spain to obtain their full cooperation with the Commission so that it will have access to certified copies of all relevant documents in those countries relating to community lands grants in the State of New Mexico. Directs the Commission to: (1) develop specified procedures for land grant evaluations, including some, acceptable to various Native American Tribes and Pueblos, that clearly protect the status quo regarding existing Indian Lands; and (2) submit the Code of Land Claims Procedure to specified congressional committees for hearings and examination, before beginning examination of specific community land claims. Makes eligible under this Act descendants of certain persons who were: (1) Mexican citizens before the Treaty; (2) members of a community land grant; and (3) U.S. citizens within ten years after the Treaty became effective. Authorizes three or more eligible descendants in 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 its duties. Authorizes appropriations.