Four military veterans whose cremated remains were left unclaimed for decades at an Oregon mental hospital will be interred with military honors on Wednesday.

The interment comes eight years after a list of 3,500 names of people who had died at Oregon State Hospital was allowed to be made public. The cremated remains are stored in numbered canisters on shelves on the hospital campus.

Most of the names on the list did not have Social Security numbers or dates of birth on file due to poor record keeping at the time. Many of the names had only the date of death to help identify them.

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“When all of this came to light, we learned the canisters that held the ashes had started to degrade and several of them were spilling out and mingling with other ashes,” Val Conley, Oregon Department of Veterans' Affairs deputy director, told NBC News. “It was awful.”

Identifying the veterans became a painstaking process of checking each name against federal military records. Two separate submissions from the state VA to the federal Department of Veterans Affairs were required. On the second submission, to the department overseeing national cemeteries, federal workers were able to finally identify the veterans in Oregon as having served their country in the military, making them eligible for the customary free military interment service.

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Identified as military veterans are Pvt. James Edward Butler, who was in the Army from 1940 to 1941; Lanier Dick Johnson, who served from 1917 to 1919 in the Navy; Sgt. William Julius Madson, who was in the Army from 1918 to 1919; and Frank John Martin, who served from 1943 to 1946 in the Navy.

According to a report on the Oregonian newspaper’s website, the list of cremains also included the name of a World War I-era veteran, Everett Irvin, who was in the Navy from 1917 to 1921 and died at the hospital in 1962. But Irvin's granddaughter, Conley said, has since come forward to indicate that her grandfather’s cremated remains had been turned over to the family in 1962 and buried.

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 “I’m just happy that we can take care of four of them and that one is already taken care of,” Conley said.

The service, at Willamette National Cemetery, will include the Oregon National Guard honor guard as well as military and civilian officials.

After the veterans are laid to rest, the flag used in the ceremony will become part of a display case in the state VA office with a plaque showing the names of the deceased veterans.

In addition to the federal VA, veterans nationwide are involved in a campaign to identify and properly bury the unclaimed remains of military veterans. In June, the unclaimed cremated remains of 13 veterans were discovered in an Akron, Ohio, funeral home.

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