ST. PAUL — Thousands gathered Saturday to protest Minnesota’s proposed Sandpiper pipeline.

The rally in St. Paul came one day after Minnesota regulators endorsed the $2.6 billion Sandpiper pipeline that would carry crude oil from North Dakota’s Bakken oil fields to Superior, Wisconsin. That’s where pipeline owner Enbridge Energy operates an oil terminal tied to other pipelines supplying refineries in the East and Midwest.

Anti-pipeline activists said they estimated around 5,000 people attended. Activists who led the battle against the giant Keystone pipeline said they hope to turn Minnesota’s pipeline into the next national organizing symbol against tar sands and climate change.

Richard Smith, who heads the group Friends of the Headwaters, said the Enbridge project could put sensitive water resources at risk.

“They shouldn’t have the right to exploit our water resources, our headwaters of the Mississippi, our lakes and streams, our wild rice and our drinking water,” he said.

Sharon Day, with the Indigenous People’s Task Force, fears expanding oil production in Canada and moving more oil through the state will hurt the environment.

“If you want your grandchildren’s grandchildren to have life, to have clean water, then we must all do what we can,” Day said.

In response to the protest, a coalition of business and labor groups released a statement saying Minnesota refineries rely on Canadian crude oil to do business.

Enbridge, a Calgary, Alberta-based energy company that operates the world’s longest petroleum pipeline network, owns six pipelines that cross Minnesota, where its operations date back to the 1950s.

Despite the drop in oil prices, Enbridge has said it is moving ahead with $44 billion in investments, including two other crude oil pipeline projects in Minnesota. Those projects — a line expansion and a line replacement — carry Canadian oil across Minnesota to Superior, including the heavy crude extracted from Alberta’s tar sands.