santa rosa memorial hospital is a 338 bed acute care hospital located in the city of santa rosa, california, which is in sonoma county. the hospital, known as "memorial", is part of the st. joseph health hospital system. it serves a population of over 500,000 people living in the greater sonoma county area. memorial hospital is the regional level ii trauma center for sonoma county, lake county, mendocino county, napa county, and the marin county coastal region.