ST. PAUL — Hundreds gathered Saturday in St. Paul to protest Minnesota’s proposed Sandpiper pipeline.

The rally took place 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.

Enbridge, a Calgary-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.

Activists who led the battle against the giant Keystone pipeline say they hope to turn Minnesota’s pipeline into the next national organizing symbol against tar sands and climate change.

While the Public Utilities Commission agreed 5-0 that the $2.6 billion, 610-mile pipeline is necessary and in the public interest, commissioners didn’t foreclose the possibility of rerouting it away from environmentally sensitive lakes, streams and wetlands. Enbridge Energy will still have to go through a lengthy review of its proposed route and a proposed alternative for part of the route that avoids some lakes and wetlands.

Enbridge argued that Sandpiper is needed to move the growing supply of North Dakota crude safely and efficiently to market. The company said it would also ease rail congestion and create about 1,500 construction jobs.

But environmentalists and tribal groups said the risk of leaks is too high, including where the route would run through the headwaters of the Mississippi River.