Here is the opinion in In re C.T. & K.:
From pages 32-33:
Paul and Alice argue that the trial court “ha[d] reason to know that an Indian child” was involved in the case—and the notice and verification requirements of subsection 1912(a) were therefore applicable—because of Myra’s testimony that C.T. is “half-Indian.” The Department, for its part, agrees that the case should be abated and remanded to the trial court for a determination as to whether ICWA applies.
We disagree that the case should be remanded or abated, however, because we do not believe that the trial court “kn[e]w or ha[d] reason to know that an Indian child” was involved in the case. See id. The only evidence adduced regarding C.T.’s heritage was Myra’s statement that Myra is “half Black Foot” and that Alice is “half Cheyenne.” She did not state that either Alice, Paul, C.T., K.T., or herself were “members” of an Indian tribe, and she did not state that either child would be “eligible for membership” in an Indian tribe. See id. § 1903(4) (defining “Indian child” as a person under eighteen who either: (a) is a member of an Indian  tribe; or (b) is eligible for membership in an Indian tribe and is the biological child of a member of an Indian tribe); see also In re Trever I., 973 A.2d 752, 758 (Me. 2009) (noting that “the party asserting the applicability of the ICWA has the burden to provide sufficient information to at least put the court or Department on notice that the child may be an ‘Indian child,’ within the meaning of the ICWA, and that further inquiry is necessary”); In re Arianna R.G., 657 N.W.2d 363, 370 (Wis. 2003) (holding that ICWA notice provisions did not apply because “the information available to the court was too vague for the court to have reason to know” that children were Indian where only evidence was father’s statement that his children have “Indian heritage” and that their “ancestry stems from the Ojibwa Tribe in Marinette, Wisconsin”).