The Supreme Court of Hawaii on Tuesday cleared the way for astronomers to build one of the largest telescopes in the world on Mauna Kea by dismissing a legal challenge of native Hawaiians aimed at blocking the project.

Justice McKenna, writing for the court’s majority in the 4-1 decision, dismissed the appellant’s claims that “Mauna Kea, as a sacred manifestation of their ancestry, should be honored in its natural state and is desecrated by development of astronomy facilities near its summit,” and affirmed the lower-court’s decision to authorizing the issuance of a Conservation District Use Permit in this instance.

The issuance of the permit has sparked significant debate and largely divided the state. Mauna Kea is beloved by astronomers for its elevation and clear skies and home of the world’s largest astronomy observatory. However, many Native Hawaiians revere the mountain for religious and cultural reasons, and burial grounds have also been discovered there. After taking all the facts into consideration, the court determined that “astronomy and Native Hawaiian uses on Mauna Kea have co-existed for many years and the TMT Project will not curtail or restrict Native Hawaiian uses.”

This ruling effectively squashing the final legal challenge to the project in the state, which has been mired in controversy since 2009. The only other option for opponents would be an appeal to the US Supreme Court, which is unlikely. Despite the win in court, the telescope backers still need to decide whether to move ahead with the project, which will cost over $1 billion.