In 1973, Michael Jarnevic enlisted in the Marines and became one of the last to serve in Vietnam. Now he is probably the last Vietnam veteran to retire.

"I don't know how you could actually prove it," Jarnevic told the Marine Corps Times, "But the onus would be to disprove it."

The 59-year-old recalls that a few Vietnam draftees served until recently. The war's last draftee, Chief Warrant Officer 5 Ralph E. Rigby, retired in November.

Jarnevic's war experiences were never limited to Vietnam. In his 42 years of service, he deployed to 37 other countries. After returning from the war, he worked as a military policeman in Colorado. A few Green Berets convinced him to join the Army Special Forces, which sent him on missions around the world. In the 1980s, he deployed to Honduras during the Contra Wars. There, Jarnevic trained local allies, a key reason he enlisted.

But his standout experience was serving in the Gulf War in 1991, where he got caught in an Iraqi gas attack. "That was a moment of terror that will always stick out in my mind," he said.

He took a break from military service to obtain a master's degree in creative writing and to teach military science and history at the University of Montana.

In 2004, Jarnevic received a notice that warned he might have to retire against his wishes. So he obtained a permit to serve through age 60.

The extension gave him the opportunity to serve as a Special Operations Task Force analyst in Afghanistan in 2012.

Jarnevic's last role was as senior enlisted adviser for the U.S. Joint Reserve Intelligence Support Element, where he coordinated analyst work against the Islamic State.

With his retirement beginning July 8, Jarnevic still wants to travel the world — but this time to less war-torn countries. He plans to use his master's degree to write about his passion—environmental conservation.

Whether or not Jarnevic is the last Vietnam veteran to officially retire, his long record of service has earned him a well-deserved discharge.

Emily Leayman is an intern at the Washington Examiner