Border security construction in Big Bend National Park has been temporarily halted, the U.S. Customs and Border Protection commissioner, Rodney Scott, said on Monday, pending a visit this week to West Texas to assess the project.

Contractors had been building a new patrol road and vehicle barriers along the border with Mexico, carving a path with bulldozers and excavators through some of the beloved park’s major natural attractions.

On Monday, opponents of the construction, who have been monitoring its progress, said the pause appeared to already be in effect.

“They’re not working. We didn’t see any contractor traffic at all,” said Jenna Cantrell, who lives in nearby Terlingua, Texas. She was in the park on Monday near Mariscal Mountain, a remote peak along the Rio Grande where construction work was taking place last weekend.

“Every day the bulldozers aren’t working is a nice day,” she said, but added, “We’re not going to rest until there’s no more contract.”

The work had drawn national attention and bipartisan criticism. Local law enforcement officials have said that the border infrastructure is costly and unnecessary in a desolate and undeveloped area where few migrants have ever crossed, even during times of peak migration.

Mr. Scott said in a video on social media on Monday that he had paused construction activity in the park Sunday night and was traveling to the Big Bend area. The pause would last until he could “do a personal evaluation” and speak with local officials, including law enforcement.

The message from Mr. Scott contrasted with a statement he put out on Thursday in which he suggested that no construction had been taking place in the park.

“What people are seeing right now is survey and design work,” he said in the statement.

The construction has proceeded based on waivers of environmental and other laws by the Trump administration for border construction. Several lawsuits have been filed seeking to halt the work in Big Bend National Park.

Federal officials are no longer planning a 30-foot wall there. Instead, they have said, contractors are building a new access road along the border, installing detection technology and erecting vehicle barriers. The park includes roughly 118 miles of the U.S.-Mexico border.

The construction has outraged many people across Texas for its speed, as well as its seeming disregard for a prized piece of untrammeled wilderness in a state without much public parkland.

Laiken Jordahl, an advocate with the Center for Biological Diversity and a former wilderness fellow for the National Park, said the pause came after a weekend of “irreversible” damage to parts of the desert ecosystem, particularly around Mariscal Mountain. The Center for Biological Diversity has filed a lawsuit seeking to stop the work.

“You can’t pick up a rock and take it home from Big Bend National Park, and yet we’re seeing these federal contractors gouging a permanent scar,” Mr. Jordahl said. Although he welcomed the pause in construction activity, he said opponents would not stop “until this whole project is scrapped for good.”