In 1986, David V. DeVault left his Providence accounting job to work at a small, publicly traded bank in Westerly. Within a year of joining the company, he was named chief financial officer. Friends asked why he would go there. They warned he would be bored.

Twenty-five years later, Devault still works for that bank in Westerly, only it’s not so small anymore. The Washington Trust Co. is now the largest independent bank with its headquarters in Rhode Island.

When he started at Washington Trust, it was one of a dozen similarly sized banks in Rhode Island. Today, most of the small banks are gone – as are most of the big banks – like Fleet, Old Stone and Hospital Trust.

That quarter century ago, Washington Trust had four branches in Rhode Island. Today it has 18 branches, with a 19th opening soon in western Cranston, to go along with four wealth-management offices, four residential-mortgage offices and three commercial lending offices, operating in three states.

In 1986, Washington Trust had fewer than 200 employees. Today it has nearly 600.

And when he began his career there, Washington Trust held $296 million in assets. Today Washington Trust, which trades on the NASDAQ under the symbol WASH, has $3.1 billion in assets – meaning the bank has grown by a factor of 10 during Devault’s time as CFO.

“If you had told me 25 years ago that we’d be a $3 billion bank, well that would have been a stretch. But the bones of the bank were very solid then, and you could see it had a lot of capacity for growth,” Devault said.

And grow it has. In the past two years alone, Washington Trust revenue grew 16 percent (2010) and 10 percent (2011), while net income grew a whopping 50 percent and 23 percent, respectively.

Washington Trust has done more than survive consolidation; it’s been an active player. The bank has acquired four financial institutions during Devault’s tenure, the most recent a 2005 acquisition of Weston Financial Group. There have been growing pains along the way, but Devault says it’s all part of the plan.