Four years ago, Bailey and Emily Radek had just participated in the Cystic Fibrosis Foundation’s Great Strides walk in honor of their classmate and family friend, Megan, who was struggling with the life-threatening autoimmune disease.

They were searching for ways to do more for Megan when they stumbled upon inspiration for a new project while visiting their grandfather in Seattle.

“We got the idea from our grandpa,” said Emily. “He would give us little (rocks painted like) lady bugs and he said they were lucky. We’d keep them in our pockets all the time.”

“That was the basis,” Bailey said. “We brainstormed from there.”

The girls, now 15 and 13, decided then to begin collecting and painting their own rocks and selling them to raise money for cystic fibrosis research and treatments. They set up shop at the Dillon Farmers’ Market two weekends in the summer, selling hand-painted stones collected from near their home in Summit Cove and the tradition was born.

Bailey and Emily now have a full-scale studio set up in their garage and hundreds of stones brought to life with brightly colored puff-paint. Some are emblazoned with positive words such as “love,” “hope” and “smile.” Others feature designs or the renderings of ladybugs in memory of their grandfather’s good-luck charms. They’ve even now branched out into the tourism markets, with a special line of “Colorado” rocks.

“They yell out, ‘Take home a piece of the Rocky Mountains,’” the girls’ mother, Tracey Radek said. “They get a lot of repeat customers.”

Last year they raised $800 for the Cystic Fibrosis Foundation, and their rocks are becoming fixtures in businesses around the county. Emily and Bailey said they sometimes walk into local stores and see their artwork sitting on the counter, and have met people who say they have a collection of painted rocks on their mantel.

“Some people just think it’s cute and sweet,” Bailey said. “And other times we’ll get people who come up and say that they have a nephew or a granddaughter (who has cystic fibrosis). We get all these really neat stories and that’s kind of motivation for not just our friend, but for everyone else.”

The sisters met Megan, who is now 14, through their mother, who is friends with her parents. The two families would get together weekly for Chinese dinners.

Megan is on an intensive treatment plan, having to take more than a dozen medications daily. She’s also an avid skier and Emily says, “she’s really nice and funny.”

In her honor, the girls spend up to 10 hours a week in their studio/garage and put in additional time collecting and washing the rocks and manning their booth at the farmers’ market. Surrounded by dozens of multi-colored rocks and under the supervision of their dog, Lucy, who is tied up nearby, they say they listen to music, eat snacks and enjoy the project.

“Sitting in a garage for a few hours has never really been a problem,” Bailey said. “It’s easy to spend a lot of time on something you enjoy doing.”

“Because painting rocks is fun,” Emily added. “It’s not like —”

“Work,” Bailey finished for her.

This year Tracey and her daughters are hoping to raise $1,500 for their team in the Aug. 10 Great Strides walk, with a matching contribution from an anonymous donor. Today will be their last day selling at the Dillon Farmers’ Market.