(FOX40.COM) — On Friday, Caltrans celebrated Isleton Bridge as it continues to connect the agricultural communities on Grand Island, around Sacramento County’s southern Delta region and San Joaquin County.

The 624-foot-long Isleton Bridge opened on Oct. 27, 1923 as a drawbridge over the Sacramento River along State Route 160.

A series of counterweights allows the double-leafed draw bridge to rise above the water and allows ships to pass up and down the Sacramento River.

According to the Library of Congress, the Isleton Bridge is one of the few remaining Strauss Heel Trunnion Bascule Bridges that has remained unmodified.

The Isleton Bridge is the second-to-last bridge along the Sacramento River before it flows under the Rio Vista Bridge, into the Delta and on to the waters of the Bay Area.

Recently two earthquakes struck near the area of Isleton, although not posing a serious risk to the historic bridge.

On Oct. 18, a 4.2 magnitude earthquake was recorded near the city and five days later on Oct. 23 a smaller 2.9 magnitude earthquake was registered in a nearby area.