PORTLAND — The reward for information leading to the conviction of the person or persons who poisoned at least eight wolves in Eastern Oregon this year has grown to $42,977.

Three groups — Wolves of the Rockies, Trap Free Montana and The 06 Legacy Project — added $10,000 to the existing reward Monday. An additional $6,977 in reward money from the Greater Hells Canyon Council, Humane Society of the United States and private donations was announced Tuesday, The Oregonian/OregonLive reported.

“We were heartbroken to hear of these horrific and inhumane killings, and condemn in the strongest terms this atrocity,” Marc Cooke, president of Wolves of the Rockies, said in a statement.

The eight dead wolves were found this year in Union County, whose largest city is La Grande. Tests at a federal lab in Ashland confirmed the animals were poisoned.

Wolves have been under different levels of protection in Oregon as their population has grown since their return in the early 2000s. The latest count, as measured at the end of 2020, put the minimum number of animals in Oregon at 173.

Last year, federal protections for wolves under the Endangered Species Act were rescinded by the Trump administration, though advocates for the animals have sued to have their protected status reinstated.

Investigators have asked anyone with information about the poisonings to contact the Oregon State Police.