The American West is battling a persistent wildfire season, with the Pacific Northwest bearing the brunt as dozens of massive blazes rage in Oregon and Washington, forcing residents from their homes and shutting down major roadways.

Several days of wildfire smoke are beginning to send more Oregonians to emergency departments and urgent care clinics, according to state health officials. The Oregon Health Authority said Wednesday that visits for respiratory illnesses are running above normal in parts of the state affected by wildfire smoke.