A Marine missing from the final battle of the Vietnam War is being laid to rest today in Denver, 37 years after his helicopter crashed in the waters off Cambodia.

Marine PFC James Jacques is being buried at Fort Logan National Cemetery with full military honors on what would have been his 56 th birthday. His remains were positively identified by the Pentagon two months ago.

On May 14, 1975, Jacques was an 18-year-old Marine serving as part of the mission to rescue the crew of the American freighter S.S. Mayaguez, which just days before had been seized in the Gulf of Thailand by the Khmer Rouge.

Jacques was part of a large Marine force assaulting Koh Tang Island by helicopter under the belief that the crew of the Mayaguez was being held there. His helicopter took heavy enemy fire and crashed into the surf with 26 men aboard. Half of those aboard his helicopter were rescued at sea, but Jacques and 12 others remained unaccounted for and were presumed dead.

The rescue mission occurred two weeks after the fall of Saigon and is considered to have been the last American military engagement in Southeast Asia. The 39 crew members of the Mayaguez were not on the island and were released a short time later by Cambodia, but 41 U.S. military service members were killed in the rescue mission.

The effort to locate the remains of those missing aboard Jacques' helicopter spanned decades, as the Department of Defense POW/Missing Personnel Office (DPMO) conducted multiple efforts with the Cambodian and Vietnamese governments to recover any remains.

In 1995, a Cambodian man stepped forward with Jacques' dog tags. That same year an underwater recovery operation at the crash site turned up remains, personal effects and debris from the crash.

On three other occasions Cambodian authorities stepped forward with what were also believed to be remains of those missing in the crash. A 2008 site investigation led to the recovery of additional remains on the island, including those of Jacques.

To positively identify Jacques' remains, scientists from the Joint POW/MIA Accounting Command (JPAC) and the Armed Forces DNA Identification Laboratory (AFDIL) analyzed circumstantial evidence and used mitochondrial DNA that matched that of Jacques' brother.

With the positive identification of Jacques' remains, only one of the 13 service members aboard Jacques' helicopter remains missing.

Air Force Maj. Carie Parker, a DPMO spokeswoman, said 1,664 American service members remain unaccounted from the Vietnam War and that "the U.S. government continues to work closely with the governments of Vietnam, Cambodia and Laos to recover Americans lost during the Vietnam War. "

In 2010, the remains of 17 unaccounted service members lost in Southeast Asia were identified by DPMO. In 2011, 25 service members were accounted for, and so far this year 22 have been identified.

Parker said the effort to identify remains from the Vietnam War has been helped by advances in DNA technology over the last 10 years, which has allowed scientists can learn more from a smaller sample.