Dozens of large wildfires roared largely unchecked across several Western states on Monday, stretching resources thin for agencies struggling to contain the flames amid a heat wave gripping the drought-parched region.

Among the areas hardest hit was northern Idaho, where an elderly evacuee was killed and at least 50 homes were destroyed by a cluster of fires that have raged along the Clearwater River in and around the Nez Perce Indian Reservation since last week.

The so-called Clearwater Complex of fires has charred more than 50,000 acres (20,000 hectares) of timber and brush and prompted the evacuation of more than 100 homes from the vicinity of the logging towns of Orofino and Kamiah, authorities said.