"Indians Welcome," reads graffiti still visible from the first annual Indigenous Peoples Sunrise Gathering on Alcatraz Island, held in 1975. That event was again celebrated yesterday, a commemoration of an important piece of Native American activist history and a crucial counterpoint to the traditional Thanksgiving celebration and narrative. That's captured in one name for the Sunrise Gathering: "Unthanksgiving."

This year, with so many indigenous Americans and climate change protesters currently fighting the Dakota Access Pipeline with protests at Standing Rock in North Dakota, the gathering took on particular resonance. But it also served also a reminder of another protest: The All Tribes group whose Alcatraz-Red Power Movement occupied the island for 19 months, from November 20 1969 to June 11, 1971.

Finally, there's also another layer to the history of Native Americans on Alcatraz. As the National Park Service recalls, before Alcatraz was the prison we mostly think of today, it was a fortress and military prison, the first on the West Coast. Most prisoners held here were US military personnel, but there were also southern sympathizers during the Civil War, and beginning in 1873, a number of Native Americans. The largest group were 19 Hopi people who had refused forced farming and "education" in government boarding schools, at which children could be beaten for speaking their native tongue.

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