Elon Musk’s tunnel-digging business no longer lists a proposed high-speed D.C.-to-Baltimore transit system on its website, and a Federal Highway Administration spokesman said the company has given the agency no indication it intends to move ahead with the project.

The Boring Company proposed digging a pair of tunnels between the two cities for use by automated electric cars traveling at speeds up to 150 mph.

The project, first outlined in 2017, garnered the support of Maryland Gov. Larry Hogan (R), and state officials granted a conditional permit for some of the work. The state also helped submit a draft environmental assessment to the highway administration, which was publicly released in 2019.

That should have teed up the federal government to decide whether the project needed a full-scale environmental review. But Doug Hecox, a spokesman for the highway administration, said the agency hasn’t taken action “because we haven’t gotten any indication from the company that they are interested in moving forward with the project.”

Hecox said the decision about whether to move forward and any timetable lay with the Boring Company. A spokeswoman for the Maryland State Highway Administration referred questions to the federal agency.

The Boring Company did not respond to requests for comment. A lobbyist whom the firm hired in Maryland said she no longer works with the company.

Bloomberg News first reported that the D.C.-area project and another in Los Angeles had been removed from the company’s website. It’s not clear when the projects were removed, but they are included in an archived version dated in February.

The initial proposal for the Maryland project involved a ­“hyperloop” — a system of electric sleds operating at up to 700 mph. But in recent years, Musk has shifted his approach, opting for cars in tunnels instead.

This month, the company finished a short tunnel network under the Las Vegas Convention Center. That project involves Teslas traveling at about 40 mph and runs for about a mile through tunnels that light up in different colors as passengers go by.

The D.C.-to-Baltimore idea began in typical fashion for Musk, an electric car and rocket entrepreneur. He tweeted in 2017 that he had secured “verbal govt approval” to build a system between New York and the District. That morphed into the Maryland project.

Even the shorter route to Baltimore is ambitious compared with the Las Vegas project, involving a link of about 30 miles. Nonetheless, the Boring Company made steps to advance it, lining up Hogan’s support, identifying property in the District for a potential station and moving ahead with permitting and the environmental review.

But the review underscored the complexity of the project, which would need the go-ahead from about half a dozen government agencies, burrowing under roads controlled by the District, Maryland, Baltimore and the federal government. Construction would have involved digging two tunnels, as well as installing stations and 70 ventilation shafts.

In Baltimore, the line would have terminated at Camden Yards, which is overseen by the Maryland Stadium Authority. Michael Frenz, the authority’s director, said Friday he hadn’t heard from the Boring Company for a couple of years.

But Frenz said he didn’t take that to mean the project wasn’t moving forward, given the technological and bureaucratic complexities involved.

“I didn’t think to call them up and say, ‘Is this project still going?’ ” he said. “I didn’t think it was necessarily something that was going to happen right away.”