More than two dozen people were detained and ticketed Aug. 29 after they blocked a Bemidji intersection for nearly four hours and called on Gov. Mark Dayton to stop the project.
The opponents say the project poses unacceptable risks of oil spills in pristine areas of northern Minnesota.
Those who pleaded guilty Friday agreed to not commit similar activity for six months. They were each given a $150 fine, with the option of doing community service instead, according to Sierra Club North Star chapter state director Margaret Levin.
Line 3, which was built in the 1960s, carries Canadian crude from Alberta through North Dakota and Minnesota to Enbridge’s terminal in Superior, Wisconsin. Enbridge says the replacement will be safer.