One lane of the three-lane bridge was closed for about two hours as the protesters braved a -19 C wind chill amid bright sunshine. Despite the disruption, the light traffic flow between 10 a.m. and noon was not held up.
The 1.3-kilometre bridge spans Halifax harbour at its narrowest point, connecting downtown Halifax with suburban of Dartmouth.
Some marchers beat drums and chanted "Idle no More" and "Protect our treaty rights." Others carried placards saying "We are the Future" and "Stop Harper."
They walked toward the downtown along Gottingen Street to the base of historic Citadel Hill, the restored British fort that overlooks Halifax.
After a few speeches and a brief prayer, the protesters made their way to the nearby Halifax Common, a large public space where they joined hands for a traditional round dance in the snow.
The protest — and several others like it across the country — was held to highlight aboriginal rights as the House of Commons resumed sitting after its holiday break.
Among those who took part in the march was Irene Lorchwauchop, a Halifax resident who said she wanted to show her support for the movement.
"I'm a white person, but I'm very grateful to the people who started this movement because everybody in this country needs to wake up to what is happening to our environment, what's happening to our atmosphere," she said.
"The threat to our survival and to our children is very serious and we don't have a lot of time left."
March organizer Shelley Young told the crowd that the Idle No More movement wasn't about to slow down.
"We're going to keep going," she yelled through a megaphone.
"This isn't going to fade out. We're going to keep going until we have change, until we can protect our land, until we can protect our water. ... We have to protect our future. We have to protect our children."
The aboriginal protesters were joined by members of a new movement called Common Causes, which describes itself as a group of social movements dedicated to defending democracy, the environment and human rights.
The group includes members of the Council of Canadians and the Canadian Union of Public Employees.
“The time has come for Canada-wide co-ordinated action against the Harper government’s agenda, which is fundamentally changing our society and our country,” Maude Barlow, chairwoman of the Council of Canadians, said in a statement.
Paul Moist, president of the Canadian Union of Public Employees, said: "We are sending a clear message today. Stephen Harper’s Canada does not reflect the values that Canadians share."