Leaders, including Prime Minister Stephen Harper, lauded Lougheed as a visionary who fought hard for Alberta's rights, but who also advocated for a strong Canada.
"This is the loss of a truly great man and that is an overused phrase in our business in politics, but Peter Lougheed was truly a giant — obviously a giant of our province, but also of our country," Harper said while in southern Quebec.
Lougheed, who was premier from 1971 to 1985, died Thursday night at the age of 84 in the Calgary hospital that bears his name.
Alberta Premier Alison Redford announced she would return home early from a trade mission to China.
"We lost a great Canadian and a great Albertan, the most influential and important in our province's history," Redford said in an audio posting to her Facebook page.
"Peter Lougheed was a visionary, an inspirational leader who forged a path for success and prosperity in our province that is unmatched and will be enjoyed by generations to come."
She also announced that Lougheed's body will lie in state in the rotunda of the Alberta legislature on Monday and Tuesday to give Albertans a chance to say goodbye.
Redford had known Lougheed from her earliest days in politics and has often spoken of him as a mentor.
Plans for a public memorial were expected in the coming days.
The condolences and remembrances from political leaders to people in the street seemed countless.
Added Harper: "I obviously will miss him as an adviser that I greatly respected.
"I can't say enough about what he has contributed. It's just one of those times when it really makes you sit back and look at the great sweep of history and what has been achieved and, in particular, to admire Peter Lougheed's role in all of that."
In Ottawa, Opposition NDP Leader Thomas Mulcair said: "Peter Lougheed’s work and achievements for Albertans and all Canadians has left an indelible mark in our collective history and will be remembered by future generations."
In B.C., Premier Christy Clark said: "Today Canada lost a true renaissance man — a leader with vision and passion, and an undeniable legacy.
"His inspired leadership laid the foundation for Western Canada's influence in Ottawa today."
In Calgary, Colleen Klein, wife to former Alberta premier Ralph Klein, said her husband developed a bond with Lougheed even before Klein became premier in 1992.
"Ralph often reflected on their relationship built during the time they worked together as mayor of Calgary and premier of Alberta to bring the 1988 Olympic Winter Games to Calgary and make these games a tremendous success," she said.
She spoke for the family as Klein is battling a form of dementia.
She said Lougheed was also a mentor and sounding board for Klein, who was premier until 2006 and took the province from the depths of low oil prices and big deficits to multibillion-dollar surpluses.
"When Ralph became premier, he and former premier Lougheed spoke on many occasions about the challenges they shared, and the Alberta they both wanted for Albertans," she said.
"Ralph, like all Albertans, understood how Peter Lougheed put Alberta on the global map, so that others, like Ralph, could follow."
Bill Smith, the president of Alberta's Progressive Conservative party, reminded party members that all they have they owe to Lougheed.
Lougheed led the fledgling PC party to victory over the Social Credit government in 1971, followed by 11 more consecutive majority victories first under Lougheed, then premiers Don Getty, Klein, Ed Stelmach and now Redford.
"The leadership of premier Lougheed built our modern party and our continued success is a credit to his vision," said Smith.
"The foundation he created has enabled us to govern well for 41 years as Progressive Conservatives."
Well-wishers took to Facebook, Twitter and the Progressive Conservative party website to offer condolences to Lougheed's family, including wife Jeanne, sons Stephen and Joseph, and daughters Andrea and Pamela.
Former MLA Jon Lord, said whether one supported or opposed Lougheed, he commanded respect.
Lord, in a posting to the PC party site, remembered the day he helped organize a march of 3,000 students to the legislature building to protest high tuition fees. Lougheed took the microphone at a hastily assembled public address system. The jeering continued.
"He shut the crowd down in five seconds flat, saying, 'I know (pause) ... I know you are going to allow me to speak' and that was it. We shut up and listened, and he was impressive.
"It was a pivotal experience that further convinced me to enter politics myself, watching how much difference one person could make in changing things for the better for everyone if given the opportunity."
Lougheed's accomplishments were many.
He became a provincial folk hero and a nationally recognized figure for his epic battles with Ottawa over control of Alberta’s oil resources. And he nurtured the oilsands development which has become a economic driver of the country.
He created a multibillion-dollar nest egg for Alberta from oil revenues and fostered arts, culture and tourism.
During the debates over patriating the Constitution, Lougheed fought for a role for the provinces and helped engineer a notwithstanding clause to ensure their rights.
He was a proponent of bilingualism and in retirement spoke out against the Kyoto accord to control greenhouse gases, but urged caution over the environmental effects from unbridled growth of the oilsands.
Although Albertans saw him as their champion, he was also remembered for his nationalism.
"He was unshakable in his belief that this country was the greatest country in the world and that it had to be united," said former Saskatchewan premier Roy Romanow, who came to know Lougheed during the constitutional debates.
"I watched his performances and they were outstanding because he understood that, in Canada, we built this country by a policy of inclusivity."
Even one-time rivals offered praise.
"We were known to have differences of opinion on occasion, but I never questioned his integrity or his motivation," said former Ontario premier Bill Davis.
Saskatchewan Premier Brad Wall lamented the loss of a mentor and a political hero.
He recalled asking Lougheed to give his members a pep talk in 2007 after the Saskatchewan Party first formed government.
"He said he would but wondered if we could afford his consultation fee. I asked him what the fee was. He said a steak sandwich," Wall said.
"His subsequent visit and the resulting discussions through the years have turned out to be the most important steak sandwich ever bought in our province."
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