Long associated with doughy dads and casual Fridays, the 28-year-old Dockers brand sought to revamp its image for a millennial audience — but a slim-cut line called the Alpha Collection, bright new colors (vermilion, anyone?), and a buzzy new slogan (“Wear the pants”) weren’t enough. Dockers discovered that the majority of its new target market was spending more than 10 hours a day on the Internet. Its slacks needed to become more social.

Previously, social media efforts made by the brand, which is owned by Levi Strauss (No. 520 in last year’s Fortune 1,000), were minimal and heavily promotional — Facebook updates often focused on free-shipping offers at Dockers.com, for example. “We were not properly strategizing and using our social efforts in the brand’s favor,” says Adrienne Lofton, Dockers’ chief marketing officer.

So last year the brand overhauled its strategy and partnered with MKG, an experiential marketing firm, to come up with ideas to bridge the digital-physical divide between its revived social channels and a multicity Wear the Pants tour. Dockers’ social feeds declared where its khaki-stocked vintage Airstream would stop next. Twitter followers who tweeted at Dockers with the hashtag #wearthepants received coupons for gear. A Dockers Facebook application and game engaged men who weren’t able to meet the tour in person. To amplify the brand’s reach, MKG used the social media management tool Sprout Social and the social media marketing platform Adaptly.

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“Showing up where our guys are allows us to reach them in an unexpected way and encourage hands-on experience with our product,” Lofton says.

Before the tour Dockers “did not have much of a voice” online, MKG president Maneesh Goyal says. But the event enabled the brand to have a sustained conversation with its customers for the first time. “We took it to a relevant place because we had something to talk about,” Goyal says. (More than 11,000 new Facebook fans, 52% more Instagram followers, and 3 million tweets mentioning @Dockers didn’t hurt either.)

Levi Strauss first made the Fortune 500 in 1969 and has appeared 30 times since. Since it dropped off the list in 2011, it has been working on a turnaround. The Dockers revamp is part of it. Selling pants wasn’t the primary goal of the brand’s social experiment, but its Alpha Collection has seen double-digit sales growth since launch. A little social media savvy was all Dockers needed. “The key is to remain on our toes, ready to flex, to uncover new ways to reach our guy,” Lofton says. Even if that’s through the device in his pants pocket.

This story is from the March 17, 2014 issue of Fortune.