Mendocino County consists wholly of the Ukiah, CA Micropolitan Statistical Area (μSA) for the purposes of the U.S. Census Bureau. It is located approximately equidistant from the San Francisco Bay Area and California/Oregon border, separated from the Sacramento Valley to the east by the California Coast Ranges. While smaller areas of redwood forest are found further south, it is the southernmost California county to be included in the World Wildlife Fund's Pacific temperate rainforests ecoregion, the largest temperate rainforest ecoregion on the planet.