The Spokane County Sheriff’s Office said 37-year-old Aaron F. Farinacci was arrested and booked on suspicion of arson in connection with the Old Trails Fire. The fires jumped roads and rivers and had burned about 12.5 square miles (about 32 square kilometers) by Monday. At least 390 square miles (1,000 square kilometers) has burned across Washington, which has contended with severe drought and a paltry snowpack. A lightning-caused fire that has burned over 530 square miles (about 1,370 square kilometers) of grassland in western Idaho and eastern Oregon continued to grow Monday. In central Utah, a blaze quadrupled in size over the weekend to nearly 109 square miles (282 square kilometers) by Monday afternoon.