It looks like the Mauna Kea observatories will be back in business after reaching an understanding with Thirty Meter Telescope protesters and law enforcement agencies over access to Mauna Kea Access Road.

The Maunakea Observatories announced Friday that they will attempt to resume normal operations, ending a nearly four-week suspension of work at the summit of Hawaii’s tallest mountain.

Rich Matsuda, chief of operations at W.M. Keck Observatory, said the decision to reopen the observatories came after safety concerns were addressed at the protest site and after state and county officials pledged support for the access arrangement.

“We are cautiously optimistic about ramping back up as close to regular operations as we can,” Matsuda said.

In a news release issued by the Maunakea Observatories, both Gov. David Ige and Hawaii County Mayor Harry Kim were quoted as calling the access breakthrough a “step forward.”

“The state stands behind the more than 500 employees’ efforts to bring the telescopes back online to begin astronomical observations again,” the governor said.

Ige added that the situation remains “inadequate for the longterm,” and he remains committed to “an immediate priority” of reopening Mauna Kea Access Road.

The largely Native Hawaiian kiai, or “protectors,” have been blocking the access road for more than three weeks in a mission to prevent work crews from reaching the construction site of the landmark $1.4 billion Thirty Meter Telescope near the mountain’s summit.

In a news conference Friday at Puu Huluhulu, protest leaders said any claims that observatory workers have been denied access is untrue. They said they’ve been allowing technicians and astronomers to pass through the blockade since the governor rescinded his emergency proclamation at the end of July.

“We hear they’re making claims about their safety,” said Lanakila Manguil, a Big Island Hawaiian cultural educator. “We’re full of aloha here.”

Manguil said that while the astronomy workers are being allowed access, the state agreed to allow only one vehicle of Native Hawaiian “protectors” onto the mountain despite a constitutionally protected right to use the ceded land.

“We are the sole ones who are being held off this mauna,” he declared.

The directors of the Maunakea Observatories made the decision to shut down July 16 shortly after hundreds of protesters took up positions blocking the access road where it intersects Daniel K. Inouye Highway, formally known as Saddle Road. Some 25 employees were brought off the mountain after it was determined that accessing the mountain was too thorny, inconsistent and potentially unsafe.

On July 23 a maintenance crew from the Gemini telescope tried to go through the blockade to address a critical issue at the summit but was denied access. Later than night the crew was allowed to go through.

After the governor called off his emergency declaration July 31, the demonstrators agreed to allow all existing observatory employees, including astronomers, to access the mountain using the Old Saddle Road and a section of bumpy, unpaved lava lined with tents, cars and people.

However, safety concerns remained, officials said, leaving the observatories reluctant to use the road and mostly only for the most pressing emergencies.

The state Wednesday laid down cinder to help smooth out the rugged lava road and also put out cones and reflectors to address safety concerns at night. The protesters also agreed to allow larger vehicles to pass through the blockade by letting them go around tents and onto the road shoulder.

“If a load is too sensitive or too large to go over the spur road, then we will make a request to law enforcement, and arrangements will be made to allow vehicles to come up the main access road around the kupuna tent,” Matsuda said.

The observatories have agreed to provide prearranged notification of all vehicles seeking access. They must contact the Office of Maunakea Management, which then contacts law enforcement officials who would provide the list to the activists.

Observatory officials said the arrangement “constitutes progress.”

“This is what we have all been collectively working on: protecting the rights of the protectors to demonstrate is our responsibility; protecting the rights of the workers at the observatories to go up the mountain to do their work is our responsibility; and protecting the rights of the public to visit the mountain is our responsibility,” Hawaii County Mayor Harry Kim said in the release.

“We’re very appreciative of the efforts by (the state Division of Conservation and Resource Enforcement) to negotiate with the protectors to regain access. This is a step forward, but still my goal is to open the mountain in protection of the rights of all others,” Kim said.

Observatory officials said they plan to send regular day crews to the summit to prepare the telescopes to resume operations. Some of the instruments were disabled to protect the health of the technology, and they will take time to restart, officials said.

“We don’t know what awaits us as far as going back online,” Matsuda said. “The observatories have a lot of complex infrastructure that have been in hibernation mode. We must check on all the equipment and make sure everything works well. During normal operations, inspections are made on a daily basis.”

At Keck, he said, as many as five astronomical instruments that are normally kept at extremely cold temperatures have warmed up. He said it could take up to a week to safely return the instruments to working order.

With good access the twin Keck telescopes could be fully operational in a couple of weeks, Matsuda said.

The four-week suspension is the longest period in the 50-year history of the mountaintop astronomy outpost that all telescopes have been simultaneously offline.