Yolo County (; Wintun: Yo-loy), officially the County of Yolo, is a county located in the northern portion of the U.S. state of California. As of the 2020 census, the population was 216,403. Its county seat is Woodland. Yolo County is included in the Greater Sacramento metropolitan area and is located in the Sacramento Valley. The majority of Yolo County remains a relatively rural agricultural region. Etymology In the original act of 1850 the name was spelled "Yola." Yolo is a Patwin Native American name variously believed to be a corruption of a tribal name Yo-loy meaning "a place abounding in rushes", the village of Yodoi, believed to be in the vicinity of Knights Landing, California, or the name of the chief of said village, Yodo. History Yolo County was one of the original counties of California, created in 1850 at the time of statehood. Government The county is governed by a board of five district supervisors as well as the governments of its four incorporated cities: Davis, West Sacramento, Winters, and Woodland. Geography According to the U.S. Census Bureau, the county has a total area of , of which is land and (0.9%) is water. Adjacent counties Colusa County - north Sutter County - northeast Sacramento County - east Solano County - south Napa County - west Lake County - northwest Transportation Major highways County roads Addressing in Yolo County is based on a system of numbered county roads. The numbering system works in the following way: North–South roads have numbers from 41 to 117 and increase from west to east. East–West roads have numbers from 1 to 38A, and then from 151 to 161, and increase from north to south. Each integer road number is generally one mile (1.6 km) apart, with letters occasionally designating roads less than one mile (1.6 km) apart. County roads entering urban areas generally become named roads once they cross a city boundary. Some examples include County Road 101 in Woodland being renamed Pioneer Ave. and County Road 102 (also known as County Route E8) in Davis being named Pole Line Road. Public transportation Yolobus (Yolo County Transportation District) runs buses throughout Yolo County and into Sacramento, and Sacramento International Airport. The University of California, Davis and the city of Davis jointly run Unitrans, a combination local city bus and campus shuttle. Fairfield-Suisun Transit Line 30 also stops in Davis on its runs