This paper addresses the question: to what extent do insights from smaller, nearshore marine protected areas (MPAs) regarding the importance of participatory processes apply to large and remote MPAs (LMPAs)? To date there has been little empirical research about stakeholder participation in LMPA designation processes outside of the Great Barrier Reef Marine Park context. Through an analysis of documents and 90 interviews collected by two independent research projects, this paper examines the designation process of a U.S. LMPA, the Marianas Trench Marine National Monument (MTMNM), which was established in the waters of the U.S. territories of the Commonwealth of the Northern Mariana Islands (CNMI) and Guam through a presidential proclamation under the U.S. Antiquities Act in 2009. Results indicate that overall the designation process for the Monument did not cohere with recommendations from nearshore MPA research about the importance of participation and transparency. Despite widespread support for conservation in that space, the proposed Monument was highly controverial. Stakeholders on all sides of the issue - advocates and opponents alike - expressed criticisms of the designation process. Concerns were related to the speed and perceived top-down nature of the process, the involvement of external entities, and the appropriateness of the process design for the local CNMI context. Data collected showed that much of the opposition to the Monument stemmed from how the process was conducted, rather than opposition to conservation. These findings suggest that a more participatory, collaborative, transparent, and culturally appropriate designation process might have achieved a similar conservation outcome while reducing conflict and enduring resentment. We derive six lessons learned from the MTMNM designation process that may be useful for LMPAs globally. Results suggest that key lessons from conventional MPAs about effective consultation and participation processes can apply to LMPAs, but also that new guidance is needed to account for the unique features of LMPAs.