Chris Wahmoff, 35, of Kalamazoo, Mich., was arrested Monday evening after spending the day inside a pipeline under construction by Enbridge Energy.
Pipeline construction was part of an overhaul of Line 6b, which ruptured in 2010 and released about 20,000 barrels of oil into southern Michigan waters near Kalamazoo. The pipeline was carrying Canadian tar sands oil, which sinks and mixes with river sediment.
Calhoun County Sheriff Matt Saxton told The Battle Creek (Mich.) Enquirer Wahmhoff was arrested but in good spirits after giving up his protest voluntarily.
"He was dirty but he appeared to be in good health," Saxton was quoted as saying.
Enbridge spokeswoman Terri Lawson told UPI in response to e-mail questions the company respected the right to protest.
"We work hard to encourage dialogue with communities and individuals in areas where we operate," she said.
Spills like the one from Line 6b and the March rupture of the Pegasus oil pipeline in Arkansas have raised concerns about the integrity of pipelines carrying heavy Canadian crude oil.
The U.S. State Department is vetting public comment on a draft review of the planned Keystone XL pipeline, designed to carry Canadian tar sands oil to southern U.S. refineries.
The Oklahoman newspaper reported from Seminole, Okla., eight protesters chained themselves to construction equipment for a few hours Monday to protest the Keystone XL pipeline.