Emergency Room - Mercy Medical Center Mt. Shasta is an emergency room that offers many services, including emergency medicine, level III trauma treatment, and an online waiting room. Visit Emergency Room - Mercy Medical Center Mt. Shasta located at 914 Pine St, Mount Shasta, CA. This Mount Shasta emergency room is one of the best in California. As part of the Dignity Health network, Emergency Room - Mercy Medical Center Mt. Shasta is dedicated to delivering high quality, compassionate care and access to Mount Shasta and nearby communities.