The Canadian province of Alberta on Monday reversed a decision that expanded access to the eastern slopes of the Rocky Mountains for openpit coal mines, but the government allowed exploration for six coal projects to continue in the area.

Premier Jason Kenney's United Conservative Party government has faced a backlash from ranchers and other Albertans who feared mines would contaminate groundwater in the picturesque foothills, after revoking a policy last year that had limited access for coal miners.

The pandemic has hit Alberta's oil-and-gas-driven economy especially hard, and Kenney's popularity has fallen sharply in polls.

"We admit we didn't get this one right and Albertans sure let us know that," Alberta Energy Minister Sonya Savage said.

Exploration for six steel-making coal projects will continue, as they previously had been approved, she said. They would face further regulatory review to begin production.

The government's original intent in revoking the 1976 policy had been to modernise it, Savage said.

Ian Urquhart, conservation director at Alberta Wilderness Association, said he was "pleasantly surprised" by the government's reinstatement of the former policy, although according to it coal mines could still be approved in exceptional circumstances, he said.

None currently operate in the eastern Rockies lands known as "Category 2."

"It's a huge sea change for this government," Urquhart said, adding that he was inundated with calls from the public with concerns about coal mines.

The Alberta government will consult the public as it develops a new coal policy, and will approve no further coal exploration applications in Category 2 in the meantime, Savage said. The government had earlier paused coal lease sales there.

The Grassy Mountain steel-making coal mine proposed by Riversdale Resources, a unit of Australia miner Hancock Prospecting, is unaffected, government officials said, as it involves a different category of land.