The Mackinac Straits Bridge extends over the Mackinaw Straits between Mackinaw City and St. Ignace, Michigan. The Mackinac Straits connects Lake Huron and Lake Michigan. The total suspension length of the span is more than a mile and a half between the cable anchors. The principle of the suspension bridge is that it has three essential parts: towers, anchorages, and cables. Towers for suspension bridges are built of stone or steel. Anchorages secure the ends of the cables, and most often are built of concrete or masonry. Cables are the most important element of a suspension bridge, since they carry the horrendous weight of the roadway.