A Yakama Nation leader, Russell Jim, has died. The 82-year-old was well-known by tribes and environmentalists across the nation for his fight to clean up Hanford.

For nearly four decades, Jim led the Yakama Nation’s Environmental Restoration and Waste Management Program. He fought to know just what the Hanford nuclear complex released into the air, water and land. And for years, Jim fought to clean it up. He also played a big role in blocking the plan to make Hanford the nation’s high-level radioactive waste repository.

In February, the Washington Legislature honored Jim with a resolution for his life’s work on Hanford and the environment.

A new documentary called “Russell Jim, A Quiet Warrior” by a Coeur d’Alene Tribal member is set to release this year. In it, Jim talks about how Hanford’s secret mission hid its many releases to the environment for decades.

Hundreds of people mourned his death at the Yakama longhouse. They followed his body in a horse-drawn procession at dawn to an Indian burial site in the nearby hills.

According to Yakama tradition, his pictures will be put away and his name won’t be spoken for a year.