The Makah Indian Tribe appeals the superior court’s order denying a constitutional writ to block a land exchange proposed by the Department of Natural Resources (DNR) and approved by the Board of Natural Resources. The land exchange, called the “Peninsula Exchange,” would exchange state forestlands with forestlands owned by a private timber company, Merrill & Ring. The Peninsula Exchange parcels border tribal lands of a number of Indian tribes, including the Makah, the Hoh, the Quileute, and the Quinault. The Makah argue that DNR violated (1) the State Environmental Policy Act (SEPA) by failing to conduct a SEPA environmental review prior to approval of the proposal and (2) the public lands management statute, Title 79 RCW, by insufficiently addressing the Makah’s concerns.

DNR’s interpretation of the SEPA categorical exemption is entitled to substantial weight and its determination that a land exchange is categorically exempt from SEPA review will be overturned only if it is clearly erroneous. We hold that DNR properly interpreted and applied the SEPA categorical exemption for state land exchanges to determine that the Peninsula Exchange was categorially exempt from SEPA review and that DNR’s finding that the Peninsula Exchange was exempt from SEPA was not clearly erroneous. Additionally, DNR complied with the public lands management statute by adequately consulting with the Makah prior to the Board’s approval of the Peninsula Exchange. Because the superior court’s decision was not manifestly unreasonable, or exercised on untenable grounds or for untenable reasons, we hold that the superior court did not abuse its discretion by denying the Makah a constitutional writ. We affirm.