The Trump administration has begun installing a border wall across a 47-mile stretch of west Texas, marking the first major construction in the Big Bend region. Landowners, environmental groups, ranchers and business owners strongly opposed the border project. Political leaders from both parties have also criticised plans for the area.

The construction forms part of the administration’s $46 billion effort to strengthen the US-Mexico border with walls, barriers, roads and surveillance technology. President Donald Trump has pledged to complete the border wall. Customs and Border Protection (CBP) said it has also doubled the pace of wall construction along the border.

CBP said “border wall panel installation is underway” in Hudspeth County, in an area identified as Big Bend 1. The agency said workers erected the first panels on Wednesday. A photograph posted on CBP’s construction update map showed a crane lifting a 30-foot steel wall panel while workers watched.

The Big Bend region covers about 500 miles across five project areas. It stretches from Hudspeth County, south of El Paso, to Lake Amistad. The latest construction is separate from a project inside Big Bend National Park. The administration has suspended that work while it seeks discussions with opponents.

Opposition to the wider border project remains strong. Landowners, environmental activists, ranchers and business owners argue that the remote region does not experience high levels of illegal immigration. US Senator John Cornyn, a Republican from Texas, has also opposed some of the administration’s plans for the region.

Activists said they would continue challenging the projects even though construction had begun. Clara Benson, a founder of the No Big Bend Wall Coalition, said the group had received reports of trucks transporting materials into the remote area along the Rio Grande. Contractors had also cleared areas to store supplies.

Speaking from Washington, D.C., where members of the coalition were meeting lawmakers, Benson said the group would continue its campaign against the wall across the region.

“We will continue to fight for this land no matter what the outcome is. We will continue fighting to the end,” said Benson. “You talk to people in West Texas, and they say even if they put it up, we’ll fight for them to take it down. So, this fight is not over.”

The administration plans to cover the border with 30-foot steel bollard walls, vehicle barriers, new patrol roads and technology to detect and deter migrants and smugglers. CBP said it is now building an average of 12 miles of barriers each week along the roughly 2,000-mile US-Mexico border.

The agency recently said it had completed 200 miles of new barriers since Trump returned to office. CBP chief Rodney Scott had earlier cited a pace of about six miles per week, making the current rate roughly twice as fast.

The wall project has also triggered disputes over environmental damage, flooding risks, sacred Native American sites and private property. Earlier this week, Big Bend landowners, ranchers and business owners, along with a nonprofit focused on protecting the region’s landscape and heritage, sued to halt the administration’s plans.