Correction: An earlier version of this story incorrectly stated that the project’s cost had gone up by a half-million dollars. It has gone up by a half-billion dollars. This version has been corrected.

Construction continues on the MGM National Harbor casino resort in Prince George’s County, Md. (MGM Resorts)

Before summer, the MGM stamp will hang atop the mammoth building under construction on the banks of the Potomac River in Prince George’s County — a sign that the region’s newest entertainment venue will soon open for business.

MGM says work on the $1.3 billion MGM National Harbor casino resort is on pace for a year-end opening, months after the August deadline set in a deal with the state’s gaming commission.

MGM had originally committed to a July debut, but company officials say that target date was unrealistic, given the magnitude of the project.

“As things got more and more real and the work got done,” it became clear that the project wouldn’t be completed until later in the year, said Suzette Meade, spokeswoman for MGM National Harbor.

The Maryland Video Lottery Facility Location Commission granted MGM Resorts International the state’s sixth and final casino license in December 2013. Under that deal, MGM is obligated to open this August, commission officials say, but the company has the option to request a six-month extension, which could give them until February.

The MGM National Harbor $1.3-billion resort casino project is set to open later this year. (Sharon Farmer/Courtesy of MGM National Harbor )

MGM plans to make that request, Meade said. In its proposal for the project, MGM had already said it would need up to 30 months to build the gaming complex, she said. Construction at the site began in May 2014.

“The 30-month period is necessary to properly construct a facility of this scope, scale and size,” she said.

Maryland Lottery and Gaming Director Gordon Medenica said in a statement Thursday that the commission has the authority to issue one six-month extension on the project “if it determines that extenuating circumstances beyond the awardee’s control” will prevent it from opening on time.

“If an extension is requested, which is expected, the Commission will carefully analyze the situation and make a decision at that time,” Medenica said.

MGM is building the luxurious casino on 23 acres overlooking the Potomac River. When complete, the casino complex will have 3,600 slot machines, 140 gaming tables, a 300-suite hotel and a 3,000-seat theater. It will be home to restaurants by culinary headliners José Andrés, Marcus Samuelsson and brothers Bryan and Michael Voltaggio.

John Rooney, the project director for MGM, said construction has had relatively few delays and that he anticipates no major complications moving forward. But he doesn’t rule out the possibility of impacts from severe weather. The Jan. 22-24 blizzard stopped work for an entire weekend, and crews dealt with snow removal for days. Work also was slow to resume as workers were unable to get to work in the aftermath of the storm.

Construction continues on the MGM National Harbor resort and casino. The Gaylord National Resort and Convention Center is in the background. (Sisson Studios /Courtesy of MGM National Harbor )

“The schedule for the project has actually stepped up recently. The contractors are working more days, more hours, additional shifts,” Rooney said. “Everybody is fully committed to working as hard and as fast as possible.”

More than 550,000 cubic yards of soil was removed from the 23-acre site, where about 1,500 contractors are now working on exterior finishes and are beginning the interior work of hanging drywall and installing millwork for the monument-like structure. Workers are halfway through putting up the glass enclosure on the 24-story hotel tower. About 400 electricians were on site last month.

The curved roof and the tower behind it already are visible to traffic from the Capital Beltway, on the Woodrow Wilson Memorial Bridge.

“A year ago, we were standing in a big hole, and now it is 24 stories plus eight stories underneath that,” Rooney said. “As we get into the summer and start doing landscaping and the finishes of the outside of the building, it is going to look more and more terrific.”

As construction continues, MGM is also readying a major effort to hire the resort’s necessary 3,600 employees. Plans are set to start preparing dealers at a training facility that MGM is slated to open as early as next month.

The company is also said to be wrapping up a transportation plan with the county and state transportation agencies that address access to the resort, road infrastructure and transit. Such a plan is critical in an area already suffering from traffic congestion, residents and community leaders say.

The project is expected to bring millions of dollars in revenue to Maryland and Prince George’s. The county’s share from tax revenue is estimated to range from $40 million to $45 million annually, and County Executive Rushern L. Baker III (D) included $19 million in casino-related revenue in the fiscal 2017 budget he unveiled Thursday. County leaders have embraced the project as an economic driver — one that could potentially draw thousands of visitors and spur more economic development in southern Prince George’s.

Bradley Frome, a top economic development official in Prince George’s who has been involved in the negotiations with MGM, said the county is doing its part to facilitate the opening by expediting permits.

“We, of course, want them to open as soon as possible,” he said. “The earlier they open, the better for the county, because it means jobs are created and revenues start coming in. But we understand this is a difficult building to build.”

MGM’s investments have already been significantly higher than what was originally proposed, some officials noted.

When MGM Resorts International unveiled architectural renderings in September 2013 for its towering casino and resort, it said it was building an $800 million resort. That price tag has gone up by a half-billion dollars.

The project costs increased as design work was refined and materials were specified, officials said. There are also cost fluctuations in labor and materials, they said.

In addition, the company made some costly adjustments to the project’s design. The earlier plan called for 3,000 slot machines, but the approved plan consists of 3,600 slots. MGM also expanded the theater from 1,200 seats to 3,000 seats to accommodate greater demand for entertainment programming at the resort.