Underappreciated and unpainted, the I Street Bridge has spanned the Sacramento River for 100 years.

Obscured by elevated Interstate 5 and overshadowed by its glitzier cousin, the Tower Bridge, the utilitarian I Street Bridge is finally getting some attention after a century of carrying trains, trucks and cars between downtown and West Sacramento.

A small photo display at the Sacramento History Museum in Old Sacramento documents the life of the brawny bridge. And this summer, a river cruise will commemorate the steel structure's 100th.

Bryanna M. Ryan, associate curator for the Center for Sacramento History, provides some answers about the I Street Bridge:

How much did the bridge cost?

(It cost) $1 million. Southern Pacific Railroad built it. Yolo and Sacramento County government ended up paying for part of the upper highway deck. It is the heaviest swing bridge in the United States.

During construction, workers would fall off. There were a couple of fatalities. But others would survive from a fall into the water from the upper deck.

Describe the bridge.

It's a steel double-decker swing bridge. The bridge swings open for boats to go up- and downriver. It rarely opens now. When it was built it was in one of the busiest areas on the river. There were barges, steamers, ferries taking people and goods up and down the river. A bridge tender sits on top and controls the opening and closing.

It's not the most beautiful bridge.

But I appreciate the bridge. It's a workhorse. It was made to last. People overlook it because it is not flashy or painted gold. It's powerful.

The 100th anniversary is pinned to what date?

We pin it to the first train to go over the bridge on April 29, 1912. A plaque on the bridge says "1911." That is probably related to the first electrical swing test, which was done in December 1911.

Bigger trucks and longer trains now travel the I Street Bridge. It's a testament to last century's bridge engineers and steelworkers, isn't it?

Definitely. There's a lot more traffic. About 10,000 cars and trucks every day. And 40 passenger and Union Pacific freight trains.

Are there people in Sacramento who don't know it is there even though it is 100 years old?

Everyone knows about the Tower Bridge. But the I Street bridge is not flashy and it's got a simple name. It sits there, doing its job, day after day.

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