Isabel Valley is a valley in the Diablo Range in Santa Clara County, California. It is also known as Santa Ysabel Valley.
The mouth of Isabel Valley lies at an elevation of 2270abbr=offNaNabbr=off. Its head is at 37.3214°N -121.4956°W at an elevation of 2480abbr=offNaNabbr=off.
Isabel Valley was used by the Five Joaquins Gang of Joaquin Murrieta to hold stolen horses until they could be driven southward on the La Vereda del Monte.[1]