California Code, Family Code - FAM § 8606.5

(a) Notwithstanding any other section in this part, and in accordance with Section 1913 of the Indian Child Welfare Act (25 U.S.C. Sec. 1901 et seq.), consent to adoption given by an Indian child's parent is not valid unless both of the following occur:

(b) The parent of an Indian child may withdraw consent to adoption for any reason at any time prior to the entry of a final decree of adoption and the child shall be returned to the parent.

(c) After the entry of a final decree of adoption of an Indian child, the Indian child's parent may withdraw consent to the adoption upon the grounds that consent was obtained through fraud or duress and may petition the court to vacate the decree.  Upon a finding that consent was obtained through fraud or duress, the court shall vacate the decree and return the child to the parent, provided that no adoption that has been effective for at least two years may be invalidated unless otherwise permitted under state law.