The Virginia Department of Transportation, which is organizing the 11 a.m. dedication at Robert Reed Park near the island library, will distribute commemorative keepsake plaques recognizing the event.
The plaques, which are 5 by 7 inches, will contain a piece of the old bridge. There will be 1,000 available and will be distributed while supplies last.
"We're hoping that every family will have an opportunity to have a piece of the old bridge," said Nora Chivers, VDOT spokesperson. "It's a piece of history."
Expected at the dedication will be state and local officials, including members of the state transportation board.
From noon-2 p.m., the public will be able to walk on the old swing drawbridge that is being replaced and have photos taken on it. The photos will be available on a website following the event.
The new bridge opened to traffic at 7:41 p.m. on April 1 after decades of planning and a $70 million construction project that lasted more than three years.
It replaces two bridges built in 1939 and 1940, which along with the causeway connected Chincoteague with the mainland.
The first bridge connecting the island to the mainland was finished in 1922.
The old drawbridge will remain open until the Marsh Island Connector is complete. Then it will be removed, Chivers said.
The bridge dedication is being held in conjunction with the island's annual Chili and Chowder Cook-off, which runs from 10 a.m. to 5 p.m. at Reed park.
The park provides a view of the past and present for those at the bridge dedication.