Mulcair, outfitted in a white cowboy hat, blue jeans and cowboy boots, rode into what could be considered enemy territory in the heart of Canada's oil country.
"I hear Mr. Harper was the one wearing the black hat last week. I'm wearing the white hat because I was told that is the tradition here in Calgary and it's fun to be here," Mulcair said.
No matter what colour the hat, Mulcair's comments about Enbridge Inc.'s Northern Gateway pipeline proposal and the energy sector's impact on the federal economy have made him public enemy No. 1 in industry circles.
Mulcair said a scathing report by the U.S. National Transportation Safety Board about how badly Enbridge handled an oil spill in Michigan two years ago should be the final nail in the coffin for the Northern Gateway project.
"What we've been talking about is protecting the northern coastline of B.C. All you have to do is look at the record of the companies that have been putting that one (project) forward, in particular Enbridge, and realize it's not our opinion. It's the opinion of the highest level of the U.S. government that they're simply not capable of doing the job properly in the U.S.," he said.
"I don't think we should be taking that risk with our ecosystems."
The proposed pipeline would carry bitumen from Alberta's oilsands to the West Coast.
Mulcair hasn't scheduled any meetings with the energy sector during his Calgary visit. He did make a call on Mayor Naheed Nenshi.
Nenshi stressed to Mulcair the importance of Northern Gateway and Alberta's oilsands.
"During our meeting, I explained how important our energy industry is for Canada’s economy and encouraged him to learn more about the industry and what is being done, or what more can be done, to ensure development that is sensitive to our environment," Nenshi said in a statement.
"The energy industry has played an important role supporting our national economy during a period of recession."
Alberta's energy minister said he has met Mulcair previously and hoped "he has a great Stampede."
Ken Hughes said Alberta welcomes "constructive" criticism when it comes to making sure resources are developed and get to market in an "environmentally appropriate way. He declined to comment on Mulcair's comments about Northern Gateway.
"I'd rather not get into a public discourse with him about his comments. What I can tell you is that a strong energy economy in Western Canada is good for all parts of Canada," said Hughes.
"We have worked as the government of Alberta to help other parts of Canada actually understand how important it is to southern Ontario, Quebec and other parts of the country, and so we have work to do to convince Canadians about the merits of what we're doing."
Mulcair said his comments about the energy sector may not be popular in Alberta, but he believes Canadians would prefer a party that is actually willing to talk about issues.
The Opposition leader has repeatedly said economic strength in Alberta, fuelled mainly by the oilsands, is jacking up the Canadian dollar and hurting manufacturers elsewhere in the country.
Alberta Premier Alison Redford said earlier this week she wasn't holding out hope that Mulcair would change his tune.
— With files from Lauren Krugel
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