For that reason, they accuse the defendants of illegally taking bull trout in violation of the Endangered Species Act. The bull trout was listed as threatened in 1999 due to the increasing loss of habitat, and in 2010, the U.S. The upper Clark Fork has had extremely low flows in 10 out of the past 16 years. A few times last year, the river flow readings below the West Side Ditch diversion dropped to single digits, according to court records. The judge also decided that the balance of hardships tips toward bull trout that have been negatively affected.