The Caltech Submillimeter Observatory has been removed from Maunakea.

Caltech officials said in statement Tuesday that all of the observatory’s facilities have been removed from the summit nearly nine years after it ceased operations at the end of 2015.

“Caltech thanks the people of Hawaii for the opportunity to explore the universe from the CSO on Maunakea, CSO director Sunil Golwala said in the statement. “It has been an honor to continue our relationship with the mauna and its people through this decommissioning effort.”

While the observatory buildings were removed from the site over the last several months, the telescope itself was removed last fall.

After the removal of the buildings, the site was graded to match the surrounding area, and will be monitored for the next three years to document the passive natural repopulation by local flora and fauna.

Caltech spent over $6 million on the decommissioning of the observatory, which began its work in 1987.

The observatory was the second of five on the mauna slated for removal as part of the University of Hawaii’s Maunakea Comprehensive Management Plan.

The first was UH’s Hoku Kea Observatory, which was removed a month ago.

Any subsequent decommissionings are pending a plan for the mountain by the new state Maunakea Stewardship and Oversight Authority, which will assume full management of the Maunakea Science Reserve by July 2028.