The Minneapolis Police Department has been quietly meeting for months with other local and federal law enforcement agencies to discuss security preparations for Super Bowl LII, which promises to be the biggest test in the history of the department.

With the opening kickoff still nearly three years away, Minneapolis officials have been assessing potential threats to the big game, which is expected to draw tens of thousands of fans to the Twin Cities.

Security has been the subject of a series of private meetings, dating to last winter, with the U.S. Secret Service, FBI and Department of Homeland Security. Another meeting is scheduled for late summer.

Thorny issues including traffic control, intelligence gathering and contingency planning in the event of a terrorist attack, or some other calamity, will have to be sorted out, officials say.

The meetings were designed to bring “together some of the key partners in law enforcement and public safety, because those are the ones you need to get things sectioned out in a number of months or years,” said Minneapolis Assistant Police Chief Matt Clark.

Given the enormity of the task, Clark said the department wanted to reach out early to federal officials to formulate a plan for how best to protect crowds at the $1.07 billion glass-walled stadium being built on the site of the Metrodome.

In doing so, the department also has sent delegations to Glendale, Ariz., which hosted the game in January, and to the 2015 National Basketball Association All-Star Game in New York. Local officials also will dispatch representatives to the 2016 Super Bowl, which will be played at the just-completed Levi’s Stadium in Santa Clara, Calif.

Clark said that security for an event of this magnitude will serve as a major test, even for a metro area that in recent years has hosted the Republican National Convention, baseball’s All-Star Game and other major cultural events.

“Without a doubt, it’s the largest thing we’ve ever done. There’s no question about it, it will tax your resources,” said Clark, who helped supervise security preparations for last year’s All-Star Game at Target Field, which drew more than 700 law enforcement officers to downtown Minneapolis. “Which is why it’s important to get out ahead of it.”

But unlike the All-Star Game, for which the department spent $121,238 in overtime costs, authorities will be spread even thinner to cover Super Bowl week festivities, which will include 50 concerts and other events across the Twin Cities, Clark said. Authorities won’t be able to simply dust off the security plan they used for previous events, he added.

Short of a presidential visit, there is no other event like the Super Bowl, he said.

Much like at the All-Star Game and the 2008 Republican Convention, hundreds of undercover and uniformed officers will likely patrol the downtown area in the days leading up to the game, ready to respond at the first sign of trouble. Video cameras will be deployed throughout the area to allow authorities to keep an eye out for trouble from a mobile command center.

Tom Tucker, director of the National Center of Biomedical Research and Training at Louisiana State University, said it was “unusual for an organization to ask for assistance this far out.”

The center has worked closely with law enforcement agencies across the country, including the Minneapolis Police Department, to certify their officers to respond to biological and chemical attacks.

Since last fall, local officers have enrolled in such courses as Biological Incidents Awareness, Law Enforcement Prevention and Deterrence of Terrorist Acts.

“It’s a Tier 1 event on the federal side, which is about as high as you can get, short of the president coming,” said Indianapolis Deputy Police Chief Mike Bates, who oversaw security at that city’s Super Bowl in 2012.

“The bottom line when you get to game day, it’s just a game,” Bates said, “so I was actually relieved when you got to game day.”