A grand opening and ribbon-cutting celebration will be held at 3:30 p.m. Thursday at the Raccoon River Park Boathouse to celebrate the opening of Athene Pedestrian Bridge, which spans the Raccoon River. The bridge connects the Raccoon River Park and Walnut Woods State Park. More than 300 individuals, businesses and organizations donated $2.8 million for the West Des Moines project that cost a total of $9.3 million to design and build. Athene USA, which has an office building in the suburb, donated $750,000 to the project. The project includes about 4,700 feet of paved trail that starts near Raccoon River Park’s entrance at 2500 Grand Ave., spans the river and ends near Hidden Valley Soccer Complex along Walnut Woods Drive. The bridge itself is 620 feet long — about 1 3/4 football-field lengths — and rests on five vertical support structures that were hammered into bedrock deep below the river bottom. The bridge structure is composed of a series of Corten steel trusses that has a thin layer of protective rust that darkens with age; the bridge’s deck is concrete. The project’s design team was led by Shive-Hattery Inc. The public is invited to attend the grand opening and ribbon-cutting celebration.