SACO — About 150 people stood on RiverWalk Bridge admiring the view of the mills that line the Saco River as Gov. Paul LePage cut a ribbon signaling the official dedication of the pedestrian structure.

The ceremony Saturday morning kicked off a day of events marking an economic collaboration between Saco and Biddeford in recent years that has breathed new life into long-idled textile mills, transforming them into housing, hotels, restaurants and office space.

“We were not sure it was going to happen in our lifetimes,” said Kati Horton.

She and her husband, Don, sat under a big umbrella on Saco Island listening to the speeches from a half-dozen politicians who were there to mark the occasion. The Hortons moved to the nearby Island Terrace Condominiums in 1988 and have kept an eye on the redevelopment of the mills ever since.

LePage said the Biddeford-Saco collaboration sets an example for other communities.

“Look what working together does,” said LePage.

Recent economic development includes a project to build a $50 million hotel complex in the former Lincoln Mill in Biddeford and the purchase of Mill Building No. 4 in Saco by Chinburg Properties, a New Hampshire firm planning to build 150 housing units, as well as stores. Both projects were spurred by the razing of the Maine Energy Recovery Co. incinerator in downtown Biddeford three years ago.

The $709,000 pedestrian bridge was completed in September 2014. Eighty percent of the construction tab was picked up by the Maine Department of Transportation. The two cities paid the rest.

The bridge – 130 feet long and 9 feet wide – opened up a new vista of the mills, their soaring brick chimneys and the falls. The bridge connects riverwalks in both cities.

Father and son Andy and Mark Libby, both of Buxton, helped build the bridge as employees of Scott Construction in Falmouth.

“I am very proud to be part of the project,” said Mark Libby.

Saco Mayor Donald Pilon and Biddeford Mayor Alan Casavant called the pedestrian bridge a symbol of the two cities’ shared history. Claude Morin, mayor of Saint-Georges, Quebec, Biddeford’s sister city, was also present.

The dedication was to be followed Saturday by a River Jam Festival until 5:30 p.m. at Mechanics Park in Biddeford featuring free music, games and food, fireworks on the Main Street bridge between the two cities at 7:15 p.m., and more of the River Jam Festival from 7:45 to 11 p.m. on Saco Island.