RED WING, Minn. – Red Wing Shoe Co. executives figured it probably wasn't young boys who were suddenly snapping up the iconic Minnesota company's $300-plus boots.

The more likely explanation for the surge in sales of men's shoes in sizes 3 and 4? Women.

There have been other tipoffs that the boots, for decades a symbol of rugged masculinity, are reaching a new audience. On Instagram, for instance, women have posted hundreds of pictures posing in the boots, often paired with rolled-up jeans or dresses, tagged under the hashtag #redwingwomen.

Now, after seeing that women account for as much as 10 percent of its Men's Heritage collection sales, Red Wing is giving women more of what they want.

The company, which has been making shoes along the banks of the Mississippi River since 1905, is launching a new line for women. The Women's Heritage boots will start showing up early next month in select Red Wing stores, on its website and at independent boutiques around the United States.

Some of the styles are nearly identical to the men's line, whereas others hearken back to boots the company made for women nearly a century ago. Others are more modern styles with modest heels that give them a more feminine spin.

The rollout is a reflection of a gender-bending fashion moment as well as of how Red Wing has transformed in recent years. The shoes, once used just in various work trades, have become a staple in the closets of hip, urban professionals who wear them to the office and on weekends.

A newer generation of fashion-focused consumers has adopted the brand not only because of its classic — and somewhat nostalgic — design, but also because the shoes are handcrafted in the United States.

Emily Otto, 38, of Shoreview, is among those waiting with anticipation for the new Red Wing women's line. She owns two pairs of the men's boots, inspired after trying on some from her husband's extensive collection of 16 Red Wings. She often gets compliments when she wears them.

"It was like a tractor beam for men. They would be like 'the 877s?' " she said, referring to one of Red Wing's more popular styles. "My husband would beam with pride."

But while she adores the rustic look, she admits wearing the men's boots has its challenges.

"I love them — but I don't wear them as frequently," she said. "They're really heavy. And you have to be super dedicated to break them in. They're getting much better now, but I've worked really hard at it."

That, in fact, is one of the biggest complaints Red Wing has heard from women. It still takes men a few weeks to a few months to break in the boots, but they tend to have an easier time at it because of their weight and because they are more likely to wear the same shoes every day.

"We deconstructed and reconstructed the shoe for women from the guts up," said Allison Gettings, Red Wing's director of product creation who spearheaded the new line.

To make the shoes lighter and more comfortable for women, Red Wing used hides from female cows, which have softer skin than steers, and made other adjustments to the leathers by working closely with its tannery on the other side of town, S.B. Foot Tanning.

Instead of the heavy rubber sole used in the men's boots, the company used a lighter polyurethane material that is more flexible and durable. They made other adjustments to the insole and cushioning. But at the same, they use the same Goodyear welting and lasts, or molds, that the company has used throughout its history to keep an aura of authenticity.

The company has factories in Red Wing and Missouri, but the women's collection is being manufactured at one of its partner factories in Arkansas that has more expertise in making women's shoes.

This is not Red Wing's first foray into women's shoes. Its first women's shoe was made in 1926 and was called the Gloria, a hiking and leisure boot. One style in the new collection is modeled after that shoe. Another design was inspired by a majorette boot Red Wing made in the 1930s for women in marching bands.

Today, women's shoes, mostly in work and hiking boots, account for 5 percent of Red Wing's overall business.

Crossing gender lines

Red Wing boots aren't the first to transcend gender. Timberland started off mostly as a style for men, but it branched out after women took a liking, said Marshal Cohen, chief industry analyst with the NPD Group. Sperry Top-Sider and L.L. Bean's shoes have had similar story lines.

One reason for the blurring of the lines is that fashionistas find ways to fill in a void when the footwear industry isn't coming up with a lot of newness, he said.

"The absence of innovation in the marketplace causes crossover to happen," said Cohen.

Part of the magic to Red Wing's recent rise in fashion circles, he added, is the element of discovery in reclaiming an older brand.

"Every generation picks something to define who they are," he said. "It's a huge opportunity for [Red Wing] to take advantage of."

The challenge is to keep the momentum going. Work boots for construction, the oil industry and other trades continues to be Red Wing's bread and butter, accounting for about 85 percent of its three-quarters of a billion dollars in annual sales.

But the fastest-growing part of its business in recent years has been its Men's Heritage collection, which now accounts for about 9 percent of its business. The line plucks out old styles from Red Wing's archives that the company produced dating back to the 1920s.

This is the line that has been embraced by the newer generation. It's a trend that actually got going in Japan back in the 1970s when people started wearing the company's work boots as a fashion statement. In the 1990s, Red Wing started making special shoes just for that country.

Finding a new market

It was those shoes that designers from J. Crew spotted on a trip to Tokyo, inspiring a partnership between the retailer and Red Wing in 2007 that continues today. That laid the groundwork for Red Wing to launch its Heritage collection in 2008. It is now sold in places like Nordstrom and Brooks Brothers as well as smaller boutiques.

Starting a women's Heritage line had been on Red Wing's wish list for awhile. But the company didn't have anyone to champion it. That person ended up being Gettings, part of the fourth generation of the Sweasy family that has owned and run Red Wing Shoes for most of its history. She had worked at the company for several years after college, then went off to launch her own line of women's shoes while living in California.

The opportunity to launch a women's Heritage collection brought her back home to Red Wing. She worked closely with Gaal Levine, a shoe designer Red Wing hired from Sperry Top-Sider, to develop the line.

"As a brand, we don't have a lot of experience with a women's-only line of footwear," Gettings said. "So it's certainly something where we're all holding our breath. But we're pretty optimistic."

Red Wing, which is typically a quiet company, won't do a big advertising push to get the word out. Instead, it's hoping to grow more slowly and organically by reaching out to influencers on social media to help spread the word.

With a devoted following, the company doesn't have to work too hard at it. The brand recently started a Red Wing Women's Heritage account on Instagram. It hasn't promoted it yet and has only posted a handful of pictures.

But its fans have found it. It already has more than 1,200 followers.

Kavita Kumar • 612-673-4113