Bismarck - The Defense POW MIA Accounting Agency reports there are 371 soldiers from North Dakota that are still unaccounted for.
Motors were revving and riding in single file to carry one flag.
Veterans rode together to honor those still lost but not forgotten.
"You look at those that are prisoners of war and you look at those that continue to be missing in action, it was an honor to be part of such an event that can reflect on those people," Ray Morrell, Commandant Department of North Dakota Marine Corps League says.
A POW and MIA flag is being carried across state lines by veterans and their supporters, riding through all 50 states.
And on its stop in North Dakota, the Marine Corp league took up the flag and called on other veterans to ride with them.
"It was an obvious marriage to invite all the other motorcycle clubs to be a part of this because we all have the same honor -- the same code of ethics -- regarding our brotherhood, our sisterhood, and our comraderies," Morrell says.
A bond that left no doubt in this veteran's mind about riding out.
"I was a military veteran for 14 years and I just can't see my brothers left behind," Scott Ellison, Vietnam Vets/ Legacy Vets Morotcycle Club says.
There are 83,000 Americans classified as prisoners of war or missing in action.
Rep. Kevin Cramer says the search for soldiers who have yet to come home should never be forgotten.
"At the very least, as a country, we have to always remember and never forget because the ultimate sacrifice is paid by lots but the lack of closure that comes with having a POW or MIA is particularly emotional for people," Rep. Kevin Cramer, (R) North Dakota says.
So veterans will keep riding out, onto the next stop, through cold and the rain.
"It's been chilly, we've had some rain, but you also think back about what those prisoners of war may have experienced this ain't nothing -- this ain't nothing, it's an honor, " Morrell says.
They'll ride out until the last soldier comes home.
North Dakota is the 10th stop on the 50 state tour.
The tour will end next year where the POW flag will be placed in the Smithsonian in honor of the soldiers that are still missing.