Some Washington state companies have expressed interest in helping build President Trump’s proposed wall on the U.S.-Mexico border, which could be a $20 billion construction project.

President Donald Trump’s promised   “big, beautiful wall” along the U.S.-Mexico border faces many unknowns, not the least of which is who will pay for it.

Still, the administration is moving swiftly to get started — and some Washington businesses are looking for a piece of the construction project, which by some estimates could cost more than $20 billion.

As of Friday, representatives of least four Washington companies had responded to a presolicitation notice on a federal business opportunities website.

The government is asking firms to submit concepts by March 10 for “the design and build of several prototype wall structures” along the 2,000-mile southern border. The Department of Homeland Security said a formal bid process would start next week, with contract awards by mid-April.

The border wall is expected to draw interest from giant design and construction companies. More than 300 companies, large and small, had responded as “interested vendors” to the presolicitation notice as of Friday.

That included Dominion Pipe and Piling, a steel supplier with locations in Auburn and Longview. The company is a subsidiary of Varsteel, a Canadian steel-services company.

“To me it’s a construction- project opportunity. We bid on projects continually. I am not looking at it politically at all,” said Brian Schuldt, Mid-West territory sales manager for Dominion, who was listed on the company’s federal application.

“If someone is going to build it, they need to have some steel,” Schuldt said.

While aware of the controversy surrounding the wall, Schuldt said border security makes sense.

“The question is, do you lock your door at night? Why? You don’t want somebody uninvited coming in your house and eating out of the refrigerator,” he said.

American Piledriving Equipment, of Kent, also signaled interest in wall-related work. The company touts itself on its website as the “world’s leading manufacturer of deep foundation construction equipment,” including the globe’s largest pile drivers.

Company President Daniel Collins did not respond Friday to a request for an interview.

Abraham Hengyucius also submitted an expression of interest in the project, under the business name Kono Fixed Income Fund of 1511, located in Bellevue. He has made news headlines in the past for business and legal troubles.

Hengyucius, formerly named Hengyu Zhang, announced plans in 2007 for construction of a major tire factory in Ephrata by his company, Washington Tire. But the project was terminated by the Port of Ephrata in 2010 over doubts about the legitimacy of the company’s incorporation, according to Rubber and Plastics News.

Another of Hengyucius’ companies, Colorado Tire, purchased a vacant federal building in Billings, Montana, in 2013. But the property went into foreclosure over unpaid taxes and was sold to an Alaskan company last year, according to the Billings Gazette.

Trump has given every indication of following through on his promise to build the border wall, which was a key plank in his presidential campaign. He signed an executive order on Jan. 25 calling for the “immediate construction” of a southern-border wall, “to prevent illegal immigration, drug and human trafficking, and acts of terrorism.”

Trump has claimed Mexico will pay for the structure — an assertion rejected by the Mexican president, Enrique Peña Nieto.

The project has been divisive. A Pew Research poll in January found 39 percent of respondents viewed a border wall as a “very important” or “somewhat important” goal, compared with 59 percent who said it was “not at all important” or “not too important.”

The poll found broader support for other actions to fight illegal immigration, including increasing the number of deportations.

Not everyone who signed up as an “interested vendor” in response to the wall presolicitation necessarily supports the project.

The Atlantic magazine’s CityLab reported that at least two of the interested contractors appear to be artists, from Germany and Virginia, “who may be trying to punk the process.” Among locals who responded, Doug Brinley, an architect and president of Mountlake Terrace’s Botic Solutions, seemed alarmed at being associated with the project when contacted by The Seattle Times.

Brinely said he enrolled in the pre-bid process to learn more about the government’s specifications for the project. He said what he found was too vague for anyone to submit a “responsible” proposal, calling the early prototypes of wall segments “nasty.”

“I am very concerned about the humanitarian and environmental aspects of a physical border,” Brinley said, pointing out that the 2,000-mile southern border varies widely.

“Creation of an artificial barrier such as this ‘wall’ can present unintended consequences. Designers need to be involved and critically engaged, especially with those we may not agree with.”