M-72–Au Sable River Bridge facts for kids
Quick facts for kids |
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M-72-Au Sable River Bridge
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 Location in Michigan
Location in the United States
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| Location |  M-72 over Au Sable River, Grayling, Michigan |
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| Area | less than one acre |
| Built | 1935 |
| Built by | F. C. Atletwed |
| Architect | Michigan State Highway Department |
| Architectural style | Steel rigid frame bridge |
| MPS | Highway Bridges of Michigan MPS |
| NRHP reference No. | 99001510 |
| Added to NRHP | December 9, 1999 |
The M-72–Au Sable River Bridge, also known as the Grayling Bridge or State Street Bridge, is a special bridge in Grayling, Michigan. It carries M-72, a main road, over the beautiful Au Sable River. This bridge is so important that it was added to the National Register of Historic Places in 1999, which means it's a historic landmark worth protecting.
Contents
A Bridge Through Time
The town of Grayling started way back in 1874, right next to the Au Sable River. Soon after, a bridge was built here to help people cross the river easily.
Growing Needs for a Bridge
As Grayling grew in the early 1900s, more and more people and cars used the bridge. The state even made the road through Grayling a "state trunkline," which is a major highway. This meant even more traffic!
In 1922, the first bridge was replaced with a stronger one. But cars and trucks kept getting heavier, and soon this new bridge wasn't strong enough either. So, in 1933, the Michigan State Highway Department designed a brand new bridge.
Building the Current Bridge
The current bridge was built by a contractor named F. C. Atletwed. It cost about $13,700, which was a lot of money back then! The bridge opened in 1935 and has been used by M-72 traffic ever since, looking almost the same as when it was first built.
What the Bridge Looks Like
The Grayling Bridge is about 40 feet (12 meters) long and 52 feet (16 meters) wide. It's built with a special design called a "rigid-frame steel stringer structure." This means the main parts of the bridge are made of strong steel and are securely connected to the supports on each side.
Nine large steel beams, called I-beams, hold up the concrete road and the sidewalks on both sides. The bridge also has fancy steel railings, which now have extra metal barriers called Armco guardrails for safety.
Why This Bridge is Special
This bridge is very important because it might be the very first "rigid-frame" bridge built by the Michigan State Highway Department. It's also the only bridge of its kind in Michigan that is made of steel, rather than concrete. This makes it a unique and historic example of bridge building!
