Whether you’re driving from Southern California or Northern California to Mammoth Lakes, the California Department of Transportation (CalTrans) is the official resource for information about California highway conditions. Use the CalTrans road conditions page to search for road conditions by searching the highways you’ll be driving on, including Hwy. 395, Hwy. 203, Hwy. 88, Hwy. 89, Hwy. 50, Hwy. 120 and other U.S. and California roadways throughout the state. You can also download the CalTrans Quick Map app on your mobile devices for quick access while you are traveling.