Throughout December dozens of Native American riders, along with supporters and friends, have ridden more than 530km across South Dakota and into Minnesota to commemorate the hanging of 38 Dakota warriors 160 years ago, 26 December 1862.

The mass hanging, the largest mass execution in US history, was the culmination of the 1862 Dakota War, also known as the Sioux Uprising of 1862 and Little Crow's War.

The ride also honours the memory of two Dakota chiefs later killed by US forces.

The conflict began when so-called "Indian agents" withheld food and supplies guaranteed under treaty with the Dakota people, with the aim of forcing the Dakota off their land.

The Sioux in North and South Dakota, Western Minnesota, and Northern Iowa are known as the Eastern Dakota and had lived there many centuries before the European invasions.

Between 1837 and 1858, the Dakota tribes agreed to a series of treaties which exchanged Dakota land for money and food.

The US government simultaneously enacted a series of policies encouraging settler migration to the area, and created the state of Minnesota.

The loss of land and an influx of colonial settlers made it difficult for the Dakota tribes to obtain food independently, making them more dependent on the supplies ostensibly guaranteed under the treaties.

Also, the US Civil War saw US authorities increasingly divert resources away from treaty obligations, leaving the Dakota on the verge of starvation.

In 17 August 1862 a desperate Dakota party took eggs from a settlement, killing settlers in the process, and Little Crow, a chief of the Mdewakanton band of Dakota, led subsequent raids.

On 23 September, federal US forces defeated the Dakota at the Battle of Wood Lake in Yellow Medicine County and three days later, the Dakota surrendered, releasing nearly 300 prisoners of war.

In November, the trials of the Dakota held prisoner began. At 498 trials held, more than 300 men were sentenced to death. The defendants had no legal representation and some of the "trials" lasted less than five minutes.

President Abraham Lincoln personally reviewed the convictions and commuted all but 39 sentences, ordering that only the Dakota involved in civilian massacres should be executed.

On 26 December 26, 1862, 38 Dakota men were hung in Mankato, Minnesota, which is where the memorial ride reaches its destination.

Those who had their sentences commuted were imprisoned at Camp McClellan in Iowa for the next four years.

Almost 1,700 Dakota women, children and elderly were held during the winter of 1862-63 on Pike Island where hundreds died from disease, hunger and exposure.

The violence against the Dakota continued despite the "end" to the war. In 1863 newspaper The Daily Republican wrote:

"The state reward for dead Indians has been increased to $200 for every red-skin sent to Purgatory. The sum is more than all the dead bodies of all the Indians east of the Red River are worth."

In April 1863 the state of Minnesota voided its treaties with the Dakota and sent those living in the camps to Nebraska, and the US Congress passed legislation making it illegal for the Dakota to live in Minnesota; which remains a law to this day.

In 2005 Lakota leader Jim Miller dreamt of Dakota people on horseback returning home to Minnesota.

Three years later the vision became a reality, with descendants of the executed men among the riders. Every December since the ride has been carried out.

This year only four of the original riders remained part of the group, and they have announced this year's commemorative ride will be the last. However, some hope younger riders will keep the tradition going.

Josette Peltier of Flandreau, a Dakota elder and Jim Miller's sister, says the ride fulfilled her brother's dream, and she's seen people change over the years.

"I've healed. I've gotten a lot of healing from this ride," she told MPR.

"And, I'm really grateful that my brother had this dream because had I not come on the ride, I don't think I would have been able to grasp my roots."

Mr Miller is now in hospital.

His nephew Todd Finney, whose Dakota name is Ta Can'te Was'te Yuha Omani (He Who Walks With His Good Heart) is one of the organisers for the ride this year.

"I just want to honor my Uncle Jim. I want to make sure we do this," he told MPR.

"We're praying for him in everything that we do, because he is such an amazing human being because he created this movement. So, even though this chapter may end, the things that he helped plan, the things that he helped do, are going to just keep continuing."

Ms RedOwl, along with her children, drives up from Nebraska each year to help the riders.

"We're here to show them that we're still here," she said.

"We're still making noise. We're not going anywhere and we're proud of who we are."