William Delmore, a longtime North Dakota attorney and former chief judge of the Standing Rock Reservation, has died after falling into a northern Minnesota lake while fishing.

Delmore, 75, was with his son at Starlight Bay Resort on Eighth Crow Wing Lake in Nevis Township late in the afternoon on May 30, when he fell into the water, the Hubbard County Sheriff’s Office said.

Shane Delmore said he and his father had been fishing on the dock, according to the Sheriff’s Office. He left briefly, then returned to the dock to find his father face-down in the water.

Emergency medical responders attempted to revive Delmore but ultimately declared him dead at the scene, the Sheriff’s Office said.

According to his online obituary, Delmore’s legal accomplishments include helping to found Turtle Mountain State Bank, the first privately owned Native American bank on tribal lands.

Along with time as chief judge of the Standing Rock Reservation, Delmore was an assistant district attorney for the Environmental Protection Agency of North Dakota, a Bismarck City commissioner and a Burleigh County commissioner. He also ran his own private law firm.

Born in Yankton, S.D., on Oct. 22, 1948, Delmore spent his earliest years on the Pine Ridge Reservation, then reconnected with his Sioux ancestry later in life, according to the obituary.