A federal judge on Monday denied a motion by environmental groups challenging oil giant ConocoPhillips’ $7 billion Willow project in Alaska’s Western Arctic. The ruling allows the construction of roads and a gravel mine planned for the last three weeks of the construction season to move forward.

The lawsuit initially filed by the groups asserted that the U.S. Department of the Interior’s approval on March 13 of the Willow project was unlawful because it did not consider reasonable alternatives to limit the harm the project would do to environmentally sensitive areas, and it failed to sufficiently consider future greenhouse gas emissions that would result from the fossil fuel extractions of the project.

“It’s heartbreaking that ConocoPhillips has been allowed to break ground on Willow before the court has fully assessed whether the project is lawful,” said Kristen Monsell, a senior attorney at the Center for Biological Diversity, in a press release. “But this case isn’t over, and we’ll keep fighting to protect struggling Arctic wildlife and our climate from this disastrous project. We’re hopeful we’ll get the Willow project’s approval thrown out once again.”

The lawsuit was filed by the Center for Biological Diversity and the Natural Resources Defense Council, as well as by Earthjustice on behalf of Friends of the Earth, Defenders of Wildlife and Greenpeace.

The mining and construction plans are scheduled for the winter habitat of high numbers of caribou, and will disrupt them.

The planned fossil fuel extraction by ConocoPhillips in the Willow project area amounts to 600 million barrels of oil, in addition to as many as three billion barrels of oil planned for the region.

“Allowing ConocoPhillips to bulldoze forward with construction of the largest oil and gas project on public lands before the lawsuits are settled is needlessly destructive,” said Natalie Mebane, climate campaign director at Greenpeace USA, in the press release. “As the largest historical emitter of greenhouse gas emissions, the U.S. cannot afford Willow or any new oil and gas projects if we’re going to avoid the worst impacts of the climate crisis. New projects will take years if not decades to complete. They do nothing to meet current energy needs. It will only deepen our dependence on expensive fossil fuels while destroying our climate, harming our health, and polluting communities.”

U.S. District Judge Sharon Gleason in Anchorage said the groups pursuing an injunction would not be irreparably harmed by the construction and that an injunction was inappropriate, reported Reuters.

“Although the White House and Department of Interior were not persuaded to stop Willow despite the advocacy of more than 5 million individuals, we are now using the power of the law to restore some balance. While this particular round of the legal challenge did not produce the outcome we had hoped for, our court battle continues,” said Erik Grafe, deputy managing attorney in Earthjustice’s Alaska Regional Office, in the press release. “We will do everything within our power to protect the climate, wildlife, and people from this dangerous carbon bomb. Climate scientists have warned that we have less than seven years to get it right on climate change, and we cannot afford to lock in three decades of oil drilling that will only serve to open the door to more fossil-fuel extraction.”

Nicole Whittington-Evans, Defenders of Wildlife’s Alaska Program director, said the environmental groups would keep fighting.

“Today’s decision is a disappointment, but we remain undeterred,” Whittington-Evans said in the press release. “We remain committed to protecting the western Arctic and look forward to the court’s full consideration of the Willow project, including its impacts to polar bears threatened with extinction and massive carbon emissions that will worsen the climate crisis for decades to come.”