The new Petitcodiac River bridge between Moncton and Riverview opened to traffic just before 3 p.m. Friday.
The opening marks the conclusion of a decades-long push to restore tidal flow to the river choked by construction of the causeway in the 1960s.
Marco Morency, a board member of the environmental group Petitcodiac Riverkeeper, says the bridge opening is a day that is a dream come true for the many people who wanted the river restored
"It's a really a community celebration today," Morency said in an interview.
"So many people [worked] really, really, really hard to make this happen. And it's a success, and it's amazing to be here to live this moment."
Provincial and municipal politicians cut a ribbon around 2:15 p.m. in the middle of the bridge.
The ceremony quickly wrapped up as more than 100 anti-vaccine protesters yelling "Freedom" drowned out speeches.
The protest was organized after false rumours spread on social media Thursday that federal Liberal Leader Justin Trudeau would cut the ribbon.
Riverview Mayor Andrew LeBlanc called it an exciting day for town residents.
"I think the causeway closure impacted our community more than others, and so our residents are really excited to have another major transportation access to Moncton open. In particular our business owners are excited to have that flow of traffic back."
Moncton's Mayor Dawn Arnold called it a historic and symbolic day for the joining of the two communities and for the environment.
"I was here almost 11 years ago when the [causeway] gates opened and something like this seemed almost unimaginable, and here we are 11 years later with a brand new bridge," Arnold said.
Silt began filling the river and fish stocks quickly declined.
"This was our environmental catastrophe that we had to change," Ronald Babin told CBC earlier this year.
In 1999, Babin helped found the Petitcodiac Riverkeeper group, which demanded steps to restore the river's ecosystem, including upgrades to the nearby wastewater treatment plant.
Years of contentious debate about whether to make changes to the causeway followed, including in the court system.
In 2007, the provincial Liberal government announced plans to restore the river and build a bridge. The causeway gates were opened in 2010 to cheers and protests.
The province financially compensated waterfront property owners along the artificial lake created by the causeway. It also spent $1.3 million to buy four homes along the river that were at risk of flooding.
Work began on the bridge in 2017 and it was expected to be complete in fall 2020.
The Progressive Conservatives delayed completion of the bridge by a year in 2019 to spread the cost out over more time.
The causeway was closed to traffic to allow for completion of the bridge approaches, removal of a temporary roadway around the construction site and realignment of the river channel under the bridge.
In 2018, the province estimated about 27,500 vehicles crossed the causeway daily, while about 26,500 vehicles crossed the Gunningsville Bridge. The closure began April 5 of this year and was scheduled to last until Oct. 5.
The total cost was about $121 million, with the bridge itself costing $61.6 million.
The name of the bridge has yet to be announced.