The doormen at Rounders Sports Bar & Grill in Mankato know a surprising number of state capitals. They can tell you about the major features of many American cities, too, and they’re well-versed on the interstate highway system.

Last year, they used that knowledge to confiscate more than 500 fake ID cards. The state Department of Public Safety last week recognized Rounders for its aggressive work in weeding out underage drinkers.

“They’re doing great,” said Terry Kelley, a special agent with the department’s Alcohol and Gambling Enforcement Division. Visiting the bar on a routine check-in, agents were amazed when the manager produced a box overflowing with fake IDs seized from underage would-be drinkers.

In the internet era, it’s easier than ever to get a fake ID, Kelley said, making it even more important for bar owners and managers to train their staff members on how to spot them.

Many with phony identification will present IDs from other states, figuring they’ll be less likely to be questioned. But Rounders has trained employees to quiz the ID holders on such things as state facts.

“Illinois is one state that’s often used for fake IDs,” Kelley said. “They’ll ask, ‘What is the state capital?’ And the kids will say ‘Chicago,’ when it’s Springfield.”

Most surprising, Kelley said, is how often students using a fake ID can’t give their correct age based on what the ID shows.

Ryan Tucker, general manager of Rounders, said his employees understand the importance of keeping underage drinkers out of the bar.

“I view it as part of my job, part of the door guy’s job,” he said. “It’s just something that falls along with the business, to comply with the law.” In a college town like Mankato, Tucker said, “the importance is a little bit more. We’re definitely under the radar a little bit more.”

In a 2015 survey of Minnesota college students, 56 percent of those between ages 18 and 20 had had an alcoholic drink within the last month, while 27 percent reported having had five or more drinks in one sitting.

Underage drinking is also a serious concern on Minnesota roads, Kelley said. In the past five years, drivers between the ages of 13 and 20 were cited nearly 7,900 times for driving while intoxicated. Underage drunken drivers were involved in 30 fatal crashes resulting in 32 deaths.

“We know this is a big problem,” Kelley said. “We ask bar employees not to look the other way.”