In July 2020, operators of the dam “stranded, suffocated and pulverized thousands of adults and juvenile fish,” according to a statement from the tribe Wednesday.

The fish kill happened the same month that the dam’s owners placed artificial turf in the river without a permit as part of a construction project. Pieces of the turf and its rubber crumbs washed down the river below the dam and into Commencement Bay. Pieces of turf remain in the river, and rubber crumbs and plastic grass fragments are “clearly visible on the shorelines and vegetation” of the Puyallup, the tribal council said in a statement.