Location: San Diego County, California

Named after a Saint Isidore (there are ten), but it is most widely believed to be for Isidorus Hispalensis, Bishop of Seville, (ca.560-636), encyclopedist, theologian, author of Etyymologiæ; (the standard Medieval glossary of the seven liberal arts) and many other works, he is the patron Saint of Farming, and the last of the Western Latin Fathers. He thoroughly reorganized the Spanish Church during the fourth Council of Toledo (633). His feast day is April 4.

This is a widely used name in this area with a creek, Indian rancheria, town, and two ridges.

USGS bench mark on summit reads "Ysidro".

Name first appears on USGS Indio Special Map (1904).

Peak was on the original 1946 HPS Peak List.