The Nevada Supreme Court adopted the Restatement (Second) of Trusts SS 338 (Am. Law Inst. 1959). It held trusts are modifiable by a settlor and beneficiary as long as any non-consenting beneficiaries' interests are not prejudiced.
Lee, Angela, "In re Frei Irrevocable Trust, 133 Nev. Adv. Op. 8 (Mar. 2, 2017)" (2017). Nevada Supreme Court Summaries. 1027.