The numbering system works in the following way: 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.

It is 79 nautical miles (146 km) northeast of San Francisco, and is centered in the California Central Valley, one of the richest agricultural regions in the world.

This table includes the number of incidents reported and the rate per 1,000 persons for each type of offense.

Yolo is a strongly Democratic county in presidential and congressional elections.

[17] In fact, since 1928, Eisenhower's win in 1952 was the only time the county was carried by the Republican presidential nominee.

In June 1978, Yolo was one of only three counties in the entire state to reject Proposition 13 (the others being San Francisco and Kern).

[24] In November 2008, Yolo was one of just three counties in California's interior in which voters rejected Proposition 8 to ban gay marriage.

[25] The 2010 United States census reported that Yolo County had a population of 200,849.

About 68.5% spoke English, 19.5% Spanish, 2.1% Chinese or Mandarin, and 1.8% Russian as their first language.

The population ranking of the following table is based on the 2010 census of Yolo County.