Here is the Washington Court of Appeals (Div. 1) decision in In re Custody of C.C.M. An excerpt:
The Mecums also claim both that ICWA requires C.C.M. to be placed according to her “best interests,” and that the standards set forth in ICWA, rather than state law, govern this dispute. The Mecums contend that because Mr. Mecum is C.C.M.’s Indian custodian, he has an equal right to custody of C.C.M. under ICWA as does Pomiak. We disagree. …
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However, ICWA itself provides a solution to this problem. The Act mandates that when either a state or a federal law affords greater protection for either a parent or a custodian, the more protective law shall apply. 25 U.S.C. § 1921. Here, Washington law accords a clear preference for parental custody. Accordingly, we hold that state law, not ICWA, supplies the substantive legal standards governing this nonparental custody dispute between an Indian custodian and a parent. In addition, because a parent’s interests in the custody and care of his or her children at stake in a nonparental custody action under chapter 26.10 RCW are equivalent to those implicated in termination and dependency proceedings, we hold that the Mecums must make their case by clear and convincing evidence.