When Scott Darnell started painting rocks and hiding them in various places across Whidbey, he never imagined nearly 14,000 people would embark on an island-wide scavenger hunt to find them. Now, some Whidbey businesses and organizations are trying to take advantage of the game’s popularity.

Oak Harbor resident Darnell started Whidbey Island Rocks, a Facebook page that has taken the island by storm, with the intention of creating an activity that pushes kids and their families out of their homes to look for the painted rocks. Those who find a rock then post their catch to the Whidbey Island Rocks Facebook page before hiding it again to continue the cycle. With every additional 1,000 new members, Darnell puts a gift basket together for the lucky hunter who finds a rock that marks the milestone. It’s been a resounding success; the Facebook group has grown to about 13,500 members in the space of three months, with 800 new members joining per month, Darnell said.

Businesses and organizations across the island, such as Clinton-based child services nonprofit Kids First, noticed the swarm of rock hunters and picked up their paint brushes. What they saw was an opportunity for free advertising.

“I think the rocks idea in general is fantastic in that it gets kids outside to explore Whidbey Island,” Tammy Scott Johnson, Kids First team member, said. “Our organization is in line with that. I saw an opportunity to get our name out to show people we’re here for the kids.”

Johnson hid rocks decorated with the Kids First logo as well as rocks advertising Children’s Day, held by the parks district, across the island. Mostly kids and their parents will be the ones who find the rocks, and that’s exactly what Johnson wants — to spread the word via rock.

Businesses on Whidbey, primarily in Oak Harbor, have used similar tactics to get the word out. Businesses like Oak Bowl and Mario’s Pizza, Pawtastic Jenn’s and Midway Florist in Oak Harbor have all decorated rocks with their brand on it, with some of them offering deals or prizes for customers who bring in the rocks decorated with their names and logos. But some say that isn’t the point of Whidbey Island Rocks.

Johnson said she faced criticism online for advertising Kids First on the rocks, but believes she was in the right since her organization supports the children scavenging for the rocks.

“We don’t want to market this as a way to advertise, but it’s a great tool for organizations and artists to get their name out,” Darnell said. “It’s a tough thing to think about because businesses probably take advantage of the opportunity, but at the same time they’re also getting people outside to look for them.”

Environmental groups on the island say the paints used for the rocks could present an environmental danger, but it would take a lot more rocks to reach hazardous levels. Stinger Anderson, administrative assistant at Washington State University Extension Island County, said he could potentially have some concerns if the group continues to grow, but he “can’t imagine” the Facebook group would get to that point. Anderson and Whidbey Environment Action Network officials weren’t concerned there would ever be enough rocks to be considered litter.

A few South End businesses, such as Crabby Coffee in Freeland and Sprinklz in Langley, have made their stores regular locations for hidden rocks, but have stayed away from advertising the businesses. Crabby Coffee owner Keasha Campbell said she puts rocks outside the coffee stand every day to educate customers about making kids on the island more active, but felt advertising through the activity “isn’t where my heart is.”

“I see it more as a charitable thing than a profitable thing,” Campbell said. “I don’t need to advertise. This puts my business name out there without even pushing advertising.”

Campbell said by churning out numerous decorated rocks and being active on the Facebook page, her business is already earning some recognition from group members. She’s noticed an uptick in customers, with many coming by to find the rocks near the coffee stand. That’s all the advertising she needed.

“We’ve become a destination for rocks, so that in itself is enough advertising for me,” Campbell said. “For me, it’s all about lighting up kids’ days.”