The Mackinac Bridge – a suspension bridge connecting St. Ignace and Mackinaw City – is as synonymous with Michigan as the Golden Gate Bridge is with California or the Statue of Liberty is with New York.

With an average of 20,000 vehicles traveling over this Michigan treasure daily, it’s critical the lights are functioning. That’s where we come in.

We’re responsible for powering the south side of the bridge. The bridge, which was opened to traffic Nov. 1, 1957, uses our primary service voltage to add equipment, such as transformers, power lighting, traffic and weather instrumentation owned by the Bridge Authority. The state entity is responsible for the preservation, maintenance, and operation of the Mackinac Bridge.

Those in the area might have noticed some work underway. We recently replaced the underground primary line that feeds the south section of the Mackinac Bridge.

“We are working closely with the Mackinac Bridge Authority and the State Park to coordinate our work and make sure travelers are safe as they go to and from the Upper Peninsula,” said Charles Stone, one of our engineering team members who helps with reliability projects in Northern Michigan.

Other recent reliability improvements include:

  • Installing a new primary underground line to feed The Colonial Michilimackinac welcome center and park area separately from the bridge.
  • Replacing a welcome center transformer and bridge primary meter equipment.
  • Rehabilitating aging equipment.

“We want to make these upgrades to our system to improve the reliability of our feeder to the bridge, so that travel across it remains as safe as possible,” Stone said.

Enjoy your drive across the Mighty Mac and count on us to light the way.

Learn more about the Mighty Mac:

Length & Span:

  • Total Length (including causeways): 26,372 feet
  • Total Suspended Span Length: 8,614 feet (7,400 feet from cable bent pier to cable bent pier)
  • Main Span (between towers): 3,800 feet
  • Vertical Clearance: 155 feet at the center of the main span, 135 feet at the boundaries of the navigation channel

Construction & Materials:

  • Towers: 552 feet above water, 210 feet below to bedrock
  • Main Cables: 42,000 miles of cable wire, 12,580 wires per cable
  • Roadway Width: 54 feet

Other:

  • Construction Cost: $99.8 million (equivalent to $828 million in 2023).
  • Named a Historic Civil Engineering Landmark: 2010