Hundreds protest tar sands in Michigan ANN ARBOR, Mich., July 15 (UPI) -- Turnout from a weekend protest near the Mackinac Bridge should serve as an indication of the growing concerns over tar sands, an advocacy director said. State chapters of the National Wildlife Federation and 350.org turned up Sunday at the north end of the Mackinac Bridge in Michigan's Upper Peninsula to protest Enbridge pipelines running through the state. Beth Wallace, Michigan coordinator for the NWF, told UPI nearly 400 people turned up at the rally to put pressure on Michigan Gov. Rick Snyder to do more on pipeline regulations. "This rally should be a wake-up call to our elected leaders that people are demanding a change in the way we view energy and energy consumption," she said Monday. Wallace said she was concerned about plans by Enbridge to increase the pressure through the pipeline system. Parts of a 60-year-old pipeline system operated by Enbridge run through the Straits of Mackinac. A section of the pipeline, Line 6b, ruptured in 2010 and released about 20,000 barrels of oil into southern Michigan waters near Kalamazoo. Enbridge pledged to make the Kalamazoo River cleaner than it was before the spill. The pipeline was carrying Canadian tar sands oil, which sink and mix with river sediment. Enbridge has conducted repairs and replacements to parts of the pipeline system since the 2010 spill.