Straits of Mackinac
The Odawa people called the region Michilimackinac, and when the British arrived, they shortened the name to what we use today: Mackinac. The pronunciation stayed French -- "Mackinaw" -- but everything else about the straits became contested ground. This narrow channel between Michigan's Upper and Lower Peninsulas connects Lake Michigan to Lake Huron, and hydrologically, the two lakes are so thoroughly joined here that scientists study them as a single body of water: Lake Michigan-Huron. Three islands guard the eastern edge of the passage -- populated Bois Blanc Island and Mackinac Island, and the uninhabited wilderness of Round Island. Between those islands and the mainland, the shipping lanes run deep and dangerous, and the history of this place is written in forts, lighthouses, shipwrecks, and one very long bridge.
Empires at the Narrows
The French established a Catholic mission at St. Ignace in 1671, planting European roots on the north shore of the straits. In 1715, they built Fort Michilimackinac on the south end of the narrows, creating a military and fur trade stronghold. When British power displaced French authority, the garrison moved to Mackinac Island in 1781, where Fort Mackinac commanded the eastern approach to the straits from its bluff. The town of Mackinaw City grew up on the southern shore around the old French fort site, which has been reconstructed and stands today as a state historic park. St. Ignace held the north. Between them, the straits have been a strategic chokepoint for over three and a half centuries -- whoever controlled this passage controlled movement between the upper and lower Great Lakes.
The Bridge and the Graveyard
The Mackinac Bridge, completed in 1957, spans the straits and physically connects Michigan's two peninsulas. But before the bridge, crossing meant ferries, ice roads, or faith. The waters below the span are not forgiving. Most of the straits have been designated the Straits of Mackinac Shipwreck Preserve, a riparian public space honoring the crews lost aboard boats and ships that went down in these treacherous shipping lanes. Lighthouses ring the passage -- McGulpin Point Light west of Fort Michilimackinac, Old Mackinac Point Light in Mackinaw City, Round Island Light visible from the ferry channel. Each marks a point where mariners once ran out of luck or navigation.
Ice and Iron
The U.S. Coast Guard patrols the straits from Graham Point in St. Ignace, and every winter the icebreaker USCGC Mackinaw, based in Cheboygan near the eastern edge, carves a shipping channel through the frozen surface. The vessel has served since the 2005-06 ice season, keeping commerce moving through conditions that would lock the straits solid. Two ferry companies -- Shepler's Ferry and the Arnold Transit Company -- operate year-round between Mackinaw City, St. Ignace, and Mackinac Island, connecting tourists and the island's year-round residents to the mainland. The straits remain a working waterway, not just a scenic one.
The Pipeline Below
Beneath the postcard scenery lies a controversy. Enbridge Line 5, built in 1953 as an extension of the Interprovincial Pipe Line Company line, enters the straits on the north shore at St. Ignace and runs along the lakebed to the south. The pipeline carries oil from Alberta to refineries in the lower Great Lakes region. In June 2019, Michigan filed a lawsuit seeking to compel its decommissioning, arguing the aging pipeline is a public nuisance that violates the Michigan Environmental Protection Act. In December 2018, Governor Rick Snyder had signed legislation establishing the Mackinac Straits Corridor Authority, charged with overseeing construction of a tunnel beneath the lakebed to house a replacement pipeline. The straits that once divided empires now divide opinion on whether energy infrastructure and freshwater ecology can share the same narrow passage.
From the Air
The Straits of Mackinac are centered at approximately 45.814N, -84.750W, connecting Lake Michigan to the west with Lake Huron to the east between Michigan's Upper and Lower Peninsulas. The Mackinac Bridge is the dominant visual landmark, spanning the straits and visible from considerable distance at cruise altitude. From 3,000-5,000 feet AGL, the narrow passage between the two peninsulas is clearly defined, with Mackinac Island and Bois Blanc Island visible to the east. Pellston Regional Airport (KPLN) is roughly 13 nm south-southwest, and Mackinac Island Airport (KMCD) sits approximately 7 nm east on the island. St. Ignace is on the north shore and Mackinaw City on the south. Ferry traffic between the mainland and Mackinac Island is often visible in the eastern straits. Fog is common, particularly in spring and fall.