Officials go through final preparations for Canada Day event in Ottawa

Jessica Mellor was doing her best Friday to catch her son, Lincoln, running as toddlers often do towards a security gate around the main Canada Day stage on Parliament Hill.

It was a tranquil moment as the family braced for the hoopla of Saturday, when half a million people are expected to gather in the shadow of the Centre Block to mark Canada's 150th anniversary an unprecedented crowd, with logistical planning and security to match.

"We've been meaning to come up for Canada Day our whole lives, basically, and never really got around to it," said Lincoln's father, Kyle, whose son is named for Lincoln Alexander, Canada's first black member of Parliament and former Ontario lieutenant-governor.

"This year, 150, it's a bit of a pilgrimage to come up and just pay homage to everything that the nation has done for us."

Officials have been working for months to prepare for this weekend's events, which the government has billed as the largest in the nation's history, between the hundreds of thousands who are expected to be in downtown Ottawa to the countless others massing in more than 2,000 communities across the country.

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On Friday, workers were putting the finishing touches on the towering main stage, where last-minute rehearsals were underway. Temporary fencing, barricades and bollards created security bottlenecks where visitors normally enjoy unfettered access to the grounds. Much of downtown Ottawa was closed to vehicles.

At one point, officers were seen peering into and under the decorative planters lining the street; a security official was heard chiding staff for letting a group walk past without being checked a group that turned out to be Environment Minister Catherine McKenna her staff.

"The hoops you have to go through, it's like a cattle shed here," Ottawa resident George Neville said of security.

"It seems extreme for a country like Canada."

Kyle Mellor, meanwhile, described it as a comfort, one he was willing to put up with.

"It's always in the back of your mind, terrible things (that could happen), but you don't want that to stop you from doing your thing, then they win. It's reassuring to see the level of security that's down here."

Tourists dressed in red or showcasing swag adorned with the Maple Leaf snapped pictures and laughed as heavily armed police manned security checkpoints nearby.

'Showcase the best of Canada'

Saturday's itinerary includes appearances by the Prince of Wales, Prime Minister Justin Trudeau, Canadian artists and U2 band members Bono and The Edge. And while Heritage Minister Melanie Joly called the preparations hectic, she said officials are more than ready.

"We want people to be able to celebrate and have fun and we want to showcase the best of Canada," she said. "That's exactly what we've been working for two years and now this is our big moment."

The weather, however, may have other ideas.

Environment Canada's forecast for Saturday includes rain in the morning and the risk of thunderstorms later in the day and into the evening, which could put a damper on plans for what has been billed as a spectacular 20-minute fireworks extravaganza.

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Only lightning or severe rain would push pause on the Parliament Hill show, Joly said; officials will adapt Saturday's festivities according to the weather.

'Reoccupation' protest

Not far from the main stage Friday, visitors to Parliament Hill gathered around a teepee set up by a group of indigenous activists to highlight some of the darker chapters in the country's history.

The Bawaating Water Protectors from Sault Ste. Marie, Ont., arrived Wednesday night, but were stopped by police. Nine people were arrested but later released, and the structure was moved closer to the main stage an exercise "reoccupation" to draw attention to the history of indigenous people.

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The Bawaating Water Protectors are just one of many indigenous groups planning demonstrations this weekend to draw attention to the fact that, for them, there is nothing to celebrate.

Trudeau visited with the demonstrators Friday, later tweeting about the meeting to say the government would be a partner in the ongoing process to break free from colonial structures and give Indigenous Peoples a space to be heard in Ottawa.

U.S. President Trump issued a statement Friday wishing Canada his best on its 150th birthday.

"The United States cherishes our relationship with Canada. Throughout the years, no two countries have formed a bond as unique as ours," the statement said.

"Canada and the United States have stood together steadfastly in times of peace and war, through prosperity and hardship. We are united by the world's longest border, but above allby the shared values we together hold so highly."