YREKA, Calif. (AP) — Fire officials say an arsonist set two wildfires in Northern California’s Siskiyou County, and they’re offering a $20,000 reward to find the suspect.

Cal Fire and the U.S. Forest Service said in a statement Thursday that the fires threatened dozens of structures, burned nearly 58 square miles of national forest land and put firefighters at great risk.

The fires began July 31 and became known as the Salmon River Complex Fire in the Klamath National Forest, and the Butler Fire in the Six Rivers National Forest. Four other fires were started in the area, but they were extinguished by first responders.

The Salmon River Complex fire is fully contained, while the Butler Fire remains 70 percent contained.