(CNN) Hundreds of protesters have blocked a road leading up to a massive telescope atop Mauna Kea, Hawaii's tallest mountain.
The blockage comes as construction of the Thirty-Meter Telescope was set to begin on the mountain. Construction crews planned to haul heavy materials on the road up to the construction site Monday.
In a series of tweets, Hawaii Gov. David Ige said the Mauna Kea Access Road is closed "until further notice." He urged drivers to "drive carefully and slow down," when in the area.
No arrests were made Tuesday, when an estimated 200 people were at the intersection of the Daniel K. Inouye Highway and Mauna Kea Access Road, according to a statement from Hawaii's Joint Information Center. But operations have been halted.
"Communication channels between the state and telescope project opponents remained open as preparations for construction continued," the release said. "The Mauna Kea Observatories announced the withdrawal of all personnel from their telescope facilities this afternoon. They anticipate returning to normal operations as soon as the situation allows."
For years, Hawaiian groups have opposed building the Thirty-Meter Telescope on top of Mauna Kea because they see the mountain as sacred. The project is expected to take until 2027.
Activist Kaho'okahi Kanuha told CNN affiliate KITV, "Money runs out; love doesn't. The question is, how committed are they to this 10-year process?"
Similar tactics worked in 2015 when construction on the $1.4 billion telescope was previously supposed to begin.
The mountain is home to a number of telescopes already. But the protesters, who have set up tents and portable toilets, are determined to dig in and do whatever it takes to keep another one from going up.
Mauna Kea is about as close as you can get to the heavens while having your feet planted on the ground.
It towers more than 6 miles above the seabed. Hawaiians consider the peak the most sacred ground in the entire Pacific. It's a burial ground for native Hawaiians' most revered ancestors, and believed to be a peak created by the gods as a place from which humans can ascend to heaven.
Mauna Kea's height also makes it sacred to astronomers, who, after a five-year search, chose the site to build the most sophisticated telescope in the world.