The Republican governor of South Dakota, Kristi Noem, has ordered two Native American tribes to remove road checkpoints they set up in an attempt to keep the coronavirus out of their reservations.
She says she will sue if they do not remove them but the tribes say they have the right to control who enters their land under federal law.
— Governor Kristi Noem (@govkristinoem) May 8, 2020
— Total Crime (@totalcrime) May 11, 2020
The Cheyenne River Sioux Tribe has rejected Mrs Noem’s ultimatum while the Oglala Sioux Tribe - which controls Pine Ridge reservation, close to the Nebraska border - has yet to respond.
It is potentially the biggest showdown between the authorities and the Native American tribes since 1973, when the Pine Ridge reservation was at the centre of a violent stand-off between the FBI and the American Indian Movement (AIM).
Two AIM activists were shot dead and 14 went missing while two FBI agents were injured in a shootout at Wounded Knee, close to the scene of the infamous massacre of hundreds of Native American men, women and children in 1890.
— tara houska ᔖᐳᐌᑴ (@zhaabowekwe) May 9, 2020
Mrs Noem, 48, was crowned Snow Queen in 1990 while at high school and has proved to be a cool and calculating politician and is an enthusiastic supporter of US President Donald Trump.
South Dakota has had more than 3,00 confirmed cases and 31 deaths but Mrs Noem has not put the state into lockdown.
She told Fox News last month: “I took an oath when I was in Congress, obviously, to uphold the constitution of the United States. I believe in our freedoms and liberties. What I’ve seen across the country is so many people give up their liberties for just a little bit of security, and they don’t have to do that.”
Last month it became the first state to hold trials to test the effectiveness of hydroxychloroquine.
On Friday, 8 May, she sent letters to the tribal leaders demanding they remove checkpoints on state highways which are designed to stop people with coronavirus coming onto tribal land.
She wrote: "We are strongest when we work together; this includes our battle against Covid-19. I request that the tribes immediately cease interfering with or regulating traffic on US and State Highways and remove all travel checkpoints."
— Native-Red Cloud "Mahpiya Luta"- 6th Gen- FM III (@Native3rd) May 10, 2020
But Harold Frazier, chairman of the Cheyenne River Sioux Tribe accused her of "continuing to interfere in our efforts to do what science and facts dictate seriously undermine our ability to protect everyone on the reservation."
Mr Frazier told the governor: "Ignorant statements and fiery rhetoric encourage individuals already under stress from this situation to carry out irrational actions. We invite you to join us in protecting the lives of our people and those that live on this reservation. I regretfully decline your request."
Residents of the Cheyenne River reservation are being allowed off it to go to medical appointments or fetch supplies but have been given health questionnaires to fill in.
Mrs Noem has had run-ins before with the tribes - in May 2019 she was told by the Oglala to stay away from Pine Ridge after she led efforts to pass a law targeting demonstrations against the Dakota Access oil pipeline.
Last month Native American tribal leaders complained about the "very slow" rate of passing out federal funding to help them tackle COVID-19.
In 1868 the United States signed the Fort Laramie treaty, creating the Great Sioux Reservation - the southern and western half of present day South Dakota.
But when gold was found in the sacred Black Hills - known as Paha Sapa - the US government reneged on the treaty, leading to a war and the Battle of the Little Bighorn, in which General Custer’s forces were defeated and killed.
The US government sent in more troops and eventually defeated Crazy Horse and his armies.
The Great Sioux Reservation was dismantled and the Lakota (Sioux) tribes were given smaller pieces of land in generally less fertile areas.
Many reservations, like Pine Ridge, suffer from endemic poverty and alcoholism.