COEUR d’ALENE — John Stone has retired three times, but the man behind the Riverstone development keeps coming back. This time, for an estimated $15 million condominium/office project.

He called it “the last piece of development that we are doing at Riverstone.

“We had to work real hard on this to get it to fit financially,” Stone said during a groundbreaking Thursday.

About 25 people attended the brief ceremony on a sunny afternoon on 3-acre chunk of green grass at the corner of Riverstone Drive and Beebe Boulevard.

“This marks the end of 23 years of development at Riverstone and we’ve been told this development has been the largest reclamation in the history of Idaho,” Stone said.

Ginno Construction is expected to begin work this month and plans to complete the project, “Cornerstone,” within a year.

“We’re glad to be part of the team,” said Kris Pereira, Ginno Construction CEO. “We think it’s a great project.”

The four-story, 60,000-square-foot building designed by Architects West will include 12 condominiums, three penthouses and office space. Century 21 Beutler and Associates is handling the marketing.

Stone said it was more than two decades ago when he surveyed the property of about 170 acres near the Spokane River, just off Northwest Boulevard and Seltice Way.

“When we took on this project it was a shuttered sawmill and mined out gravel pit,” he said.

Looking at it today, Stone said he and his team have “come a long ways.”

Today, it’s home to businesses, shops, condos, apartments, health care and financial professionals, hotels, restaurants and a manmade lake.

Stone said Riverstone has been a driver behind economic development in Coeur d’Alene.

“We had a dream of building a project that was a live, work and walk project and we think that we’ve accomplished that,” he said.

Nikole Cummings of Riverstone Holdings has worked with Stone nearly 20 years.

She said it’s been wonderful to watch the property's transformation over the years.

She said this final project will be “something we can hang our hat on.

“It’s completely unique in Coeur d’Alene. There’s no other building like it,” she said.

Ryan Martin, a project manager, has worked with Stone 20 years.

“This is kind of the center jewel to Riverstone,” he said.

Martin called Stone a “visionary.”

“Now we have what we have here,” he said.

The Cornerstone “means we’re going to bring another great project to Coeur d’Alene,” he said.

Stone was pleased to reach this point.

He said “these are wild and uncertain times in the economy.”

“This last project has been one of the most difficult projects to birth because working to get entitlements seems to be getting more and more difficult every year,” he said.

The trying times brought him out of retirement for the third time, he said, “and hopefully the last one.”

“He says he’s going to retire again,” Cummings said, smiling. “We’ll see.”