43 CFR 11.14(w)

Lead authorized official means a Federal or State official authorized to act on behalf of all affected Federal or State agencies acting as trustees where there are multiple agencies, or an official designated by multiple tribes where there are multiple tribes, affected because of coexisting or contiguous natural resources or concurrent jurisdiction.

15 CFR 990.14(a)

1. If an incident affects the interests of multiple trustees, the trustees should act jointly under this part to ensure that full restoration is achieved without double recovery of damages. For joint assessments, trustees must designate one or more Lead Administrative Trustee(s) to act as coordinators.

2. Trustees may develop pre-incident or incident-specific memoranda of understanding to coordinate their activities.