Notice to Cease and Desist pursuit of TMT construction on Maunakea

A Notice to Cease and Desist in pursuing construction of the Thirty Meter Telescope on Maunakea was served to the TMT International Observatory LLC on Tuesday. 

Puʻuhonua o Puʻuhuluhulu delivered the demand in its ongoing effort to prevent desecration and overdevelopment atop the mountain it considers sacred.  “There is a vast, significant contingent of Native Hawaiians and their allies who are strongly opposed to the massive TMT being built on Maunakea,” the group stated in the notice.

The group also enclosed a petition containing more than 500,000 signatures in opposition to the project, which it has been fighting to stop for over a decade.

Advocates have called the project a next-generation telescope saying it can uniquely serve as a window into the universe.

Civil Beat reports that the TMT project is back under consideration for federal support, but it must complete a final design phase without taxpayer assistance.

The project’s primary site is Maunakea, and the backup site is ORM in Spain. The Maunakea site is at a higher altitude, has favorable adaptive optics, and superior atmospheric characteristics, according to project updates.

Project managers have said their biggest challenges have been access and federal funding. Project Manager Fengchuan Liu, who spoke during a University of Hawaiʻi Board of Regents meeting in May, said the group sent an inquiry to UH in October of 2025, asking about the possibility of building the TMT on a decommissioned site. A decision on revising the location had not been made and would require unanimous approval from the TMT board.

During a webinar update last year, he noted that the team is committed to working with Native Hawaiians “in the most respectful way to co-create a future that uplifts all.”

The historical opposition and public protests at Maunakea spans back several decades.

“The TMT project has faced continuous delays since 2011 due to legal challenges, contested case hearings, arrests, and front-line actions by kiaʻi (protectors) who shutdown the 2014 groundbreaking event, halted construction crews in 2015 and prevented heavy equipment in 2019 from accessing the summit,” according to the notice.

The group says the proposed TMT project presents “serious risks” that its says can’t be remedied or mitigated. “Further development on Maunakea would cause lasting and detrimental impacts to Native Hawaiian cultural practices, sacred sites, and generational connections to the mountain, while raising serious concerns regarding the constitutionally protected rights of Native Hawaiian cultural practitioners. No mitigation efforts or strategies could lessen these impacts,” the group explained.