An incredibly rare white bison calf has been photographed in Yellowstone National Park, exciting Native American tribes who view its arrival as a religious prophecy heralding major change.

It was spotted in the Lamar Valley area of the park, making it the first white bison to be born from the last wild herd in the US, according to modern records.

Other white bison births in recent decades occurred in captivity and from parents that contained domestic cow DNA – making the wild spotting more religiously significant for tribes.

Montana photographer Erin Braaten took photos of the young buffalo in the Lamar Valley on 4 June while visiting the park with three of her eight children.

Stuck in traffic caused by a slow-moving bison herd, she noticed the young calf across a river, nearly 100 metres (330ft) away, and initially mistook it for a coyote because of its sandy light colour.

“There were so many different thoughts and emotions,” Mrs Braaten, who grew up hearing about the sacred white bison calf, told the BBC.

“It was so amazing. I thought I’d have a better chance of capturing Bigfoot than a white bison calf,” she adds.

The birth of a white buffalo is a sacred event for many Native tribes of the Great Plains, including the Lakota people, who believe that it relates to a time around 2,000 years ago when food was scarce and the bison were rarely seen.

The Lakota legend tells of a beautiful woman who appeared and delivered the gifts of a sacred pipe and bundle to the people. The woman told them she would return to restore harmony in a troubled world, and then rolled on the ground four times, changing colour each time before becoming a white buffalo calf.

Her departure led the bison to return, and white buffalos are now seen as a sign that prayers are being heard and that change is coming.

The white buffalo woman is considered the central prophet – a messiah-like figure – in the theology of many tribes, including the Sioux, Cherokee, Comanche and Navajo.

Her story is often likened to that of Jesus Christ in the Christian faith.

Simon Moya-Smith, an Oglala Lakota writer who was also raised on the white buffalo woman’s story, told the BBC the arrival of a white calf is seen both as a “blessing and a warning”, according to tradition.