Elevation: 3,207 ft (977 m)
Echo Mountain is a summit on the Angeles National Forest above Altadena, California.
Echo Mountain was shaped from an alluvial fan between Rubio and Las Flores canyons. It is geographically defined by Castle Canyon to its leeward side, Rubio Canyon at its foot, and Las Flores Canyon on its windward side. Echo has a mean elevation of 3,207 feet (977 m) above sea level. It is most visible as a short mountain extension whose ridge protrudes below the peak of Inspiration Point.
Echo Mountain's name is derived from the number of repetitions one's voice could emit into Castle Canyon. Boy Scout projects were made to find the "sweet spot" where the largest number of repetitions could be heard. During the days of the Mount Lowe Railway "echophones" were set up to assist in voice projections near the best sweet spots.