After seeing the dozens of people hard at work in the posh East Sonora headquarters of UV Skinz on Monday, it’s hard to imagine that the company was being operated out of a barn structure on the founder’s property just under two years ago.

Rhonda Sparks, 45, of Sonora, founded UV Skinz in 2005 following the untimely death of her first husband to skin cancer four years earlier. Now, the company has sold millions of sun-protective pieces of clothing intended to help prevent the same from happening to other families.

“Every unit we send out the door, we call them sun-protective soldiers,“ Sparks said. “Each piece we ship is going to protect a child, a mom, a dad, or a grandparent.”

Sparks said the company employs more than 30 people at its 8,000-square-foot office and warehouse off Camage Avenue.

The company moved into the new digs, which was designed with the help of contractors Plum Construction and Canavan Woodworks, in August 2015.

“We’re in rapid growth every year,” Sparks said. “At least double digit, if not triple, in the 12-year history of this company.”

Starting out selling nylon and Lycra short-sleeved and long-sleeved shirts, the company has since expanded its product line to include shorts, pants, hats, hoodies, shoes and more.

All of the clothing is certified to provide an Ultraviolet Protection Factor of 50-plus, which means 98 percent protection from UVA and UVB sun rays.

Sparks said most of the focus is on swimwear as more than 80 percent of customers said they were using the company’s products for water play.

“That’s when you’re most exposed to UV rays,” Sparks said.

Over the years, the company’s products have been featured in publications such as People Magazine, Redbook, InStyle, Buzzfeed and the Wall Street Journal, as well as television shows such as ABC’s “The View” and the “TODAY Show” on NBC.

Sparks said some of the company’s famous clients have included actor Matthew McConaughey, actress Alyssa Milano, and rapper Macklemore.

The company’s main point of sales is in the United States, but it also has distribution in places such as Japan, Mexico, Canada, the United Kingdom and Peru.

While a big piece of the business is direct-to-consumer through the company’s website and e-commerce websites such as Amazon, Sparks said one of her biggest accounts has been with Costco for the past seven years.

“They really want to help us raise awareness,” Sparks said. “It’s a good partnership.”

Raising awareness about the risk of skin cancer is one of the driving forces behind the company.

More than 4 million cases of skin cancer are diagnosed every year in the United States, according to the Skin Cancer Foundation. That includes more than 87,000 cases of melanoma, the deadliest type of skin cancer.

The Skin Cancer Foundation says one person dies of melanoma nearly every hour, with 86 percent of cases attributed to exposure to ultraviolet radiation from the sun. A person’s risk for contracting the disease doubles if they’ve had more than five sunburns, according to the foundation.

“A generation ago, most people just thought a sunburn turned into a tan,” Sparks said.

Sparks became aware of the dangers after her first husband, Darren Farwell, came home one day with a mole on his back. He was 27 and she was 25 at the time, so they thought the doctor would just remove it and everything would be fine.

Farwell was diagnosed with melanoma skin cancer in 1996 and, two years later, it moved into his lymphatic system. He died on Sept. 14, 2001, after a five-year battle with the disease, leaving behind Sparks and their three children, Ethan, who was 6 at the time, Seth, who was 3, and Caleb, who was 1.

A section on the company’s website is dedicated to Farwell, and his story is included in all of the company’s catalogs.

Sparks remarried 11 years ago to John-Jay Verheul. They have since had two more children, Jesse, 9, and Cassidy 7. Her three sons with Farwell are now all young adults or in their late teens.

“The older boys are getting to the age where they understand the purpose and volume” of the UV Skinz brand, Sparks said.

Sparks said she believes entrepreneurship is in her DNA because her parents both had businesses while she was growing up in Foster City near San Mateo. She also earned a bachelor’s degree in business from Golden Gate University.

Sparks previously also ran a conference-calling service that recently closed its doors after 21 years in business.

Sparks said she moved to Sonora with Farwell after their first child was born to raise a family in a better environment than the Bay Area at the time.

Before launching UV Skinz, Sparks said she previously never worked in the fashion industry and had discussions with her management team about whether an apparel company would work in the foothills.

A challenge was recruiting people with expertise in the industry, so she had to bring people in from outside of the area and work with contractors.

However, the risk paid off, and UV Skinz is planning to break ground in the next few months on a new warehouse next door to the current one.

Sparks credits the success of her company to her persistence, her team and some help from organizations in the community, specifically citing Larry Cope of the Tuolumne County Economic Development Authority, whom she said she meets with often.

“My feeling is you can do anything you set your mind to,” Sparks said. “I wanted to raise a family up here, so I was going to start a business up here and I wasn’t going to let anyone stop that.”