San Francisco, California – The memories come back in flashes: the ink-black night, the whipping cold, the dark waves lapping at the side of the boat as Tashina Banks Rama stepped on board.

Tashina was only a child when it started. But every November, on Thanksgiving Day, she and her younger sister would blink awake in the early hours of the morning to join her parents on the edge of the San Francisco Bay.

It was always freezing, always quiet, at least at first.

As she hopped from the pier to the ferry, Tashina remembers hearing the water splashing below. Pendleton blankets and star quilts, patterned with radiating bursts of colour, would rustle out from bags as families piled on board. And as the streetlights and towers of the city faded behind them, a sudden drumbeat would rupture the silence.

Before them loomed a jutting rock, Alcatraz Island, surging out of the waves. The air felt heavy with intention as the boat lurched forward.

“All of a sudden, you have this feeling, this presence of spirituality and ceremony — that this is something serious we’re doing,” Tashina, now 51, recalls.

“Even if you might not know who you’re with, you feel very safe because you’re all there for the same purpose.”

For nearly half a century, Alcatraz — best known for its infamous prison — has played host to an annual Indigenous tradition: a sunrise ceremony to greet the morning’s first rays of light.

For some, it is a day of thanks, a time to honour Indigenous ancestors and celebrate the continued survival of tribal nations across the Americas.

For others, it is a moment of “un-Thanksgiving”: an Indigenous response to the sanitised depictions of colonisation associated with the Thanksgiving holiday.

But this Thursday, as the sun rises on Alcatraz once more, longtime participants fear a new threat may end the gathering for good.

In May, United States President Donald Trump announced on social media that he had directed the Bureau of Prisons to “reopen a substantially enlarged and rebuilt ALCATRAZ, to house America’s most ruthless and violent Offenders”.

The plan has been widely denounced as impractical. The last penitentiary on the island closed in 1963 because of its dizzying operating costs, which were triple that of other federal prisons in the US.

There is no local source of fresh water on the island, and basic supplies have to arrive by boat. One estimate put the price tag for redeveloping Alcatraz at $2bn.

Still, Trump has maintained he plans to move forward, even sending his interior secretary and attorney general to scope the terrain in July.

But for Tashina, the loss of the island would mean the loss of a spiritual tradition that connects her to generations of Indigenous activists, including her father, American Indian Movement (AIM) founder Dennis Banks. The thought alone fills her with grief.

“It made me — and it actually still makes me — very sad,” she said of Trump’s order. “Thousands and thousands of prayers have taken place from that spot. It’s a sacred place.”