The Elsinore Mountains are a

ridge A ridge or a mountain ridge is a geographical feature consisting of a chain of mountains or hills that form a continuous elevated crest for an extended distance. The sides of the ridge slope away from the narrow top on either side. The line ...

of mountains within the larger range of the

Santa Ana Mountains The Santa Ana Mountains are a short peninsular mountain range along the coast of Southern California in the United States. They extend for approximately southeast of the Los Angeles Basin largely along the border between Orange and Riverside co ...

, in the

Cleveland National Forest Cleveland National Forest encompasses 460,000 acres (), mostly of chaparral, with a few riparian areas. A warm dry mediterranean climate prevails over the forest. It is the southernmost U.S. National Forest of California. It is administered by th ...

Riverside County, California Riverside County is a County (United States), county located in the southern California, southern portion of the U.S. state of California. As of the 2020 United States Census, 2020 census, the population was 2,418,185, making it the fourth-most ...

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

. the tallest peaks within the range is the unofficially named

San Mateo Peak San Mateo Peak is the unofficially named peak, at the western end of the ridge running west then northwest from Elsinore Peak to Morrell Canyon, south and west of the Morrell Potrero in the Elsinore Mountains of the Santa Ana Mountain Range. ...

at .USGS Map Name: Sitton Peak, CA Map Center, N33° 36' 47" W117° 22' 44" from topoquest.com accessed on 4/22/2013
/ref> Second is officially named

Elsinore Peak Elsinore Peak is a named summit, at the southern end of the mountain ridge running southeast from the vicinity east of El Cariso in the Elsinore Mountains, in Riverside County, California in the United States The United States of Ame ...

at . The Elsinore Mountanins run in a ridge from just east of El Cariso, southeast to Elsinore Peak. Beyond that peak the ridge begins to descend and curves to the east. From Elsinore Peak, a ridge runs to the west and then northwest to San Mateo Peak, enclosing the Morrell Potrero on the south and west. Canyon_lake_view_to_west_1

Decker Canyon Creek and Morrell Canyon Creek, tributaries of

San Juan Creek San Juan Creek, also called the San Juan River, is a long stream in Orange and Riverside Counties, draining a watershed of .7.5 Minute Quadrangle Map, U.S. Geological Survey, San Juan Capistrano, 1968, photorevised 1981 Its mainstem begins in ...

, and San Mateo Creek have their sources on the western face of the Elsinore Mountains. Los Alamos Canyon Creek, and its tributary Wildhorse Canyon Creek, tributaries of San Mateo Creek, drain its south facing slopes. The

ephemeral Ephemerality (from the Greek word , meaning 'lasting only one day') is the concept of things being transitory, existing only briefly. Academically, the term ephemeral constitutionally describes a diverse assortment of things and experiences, fr ...

streams on the eastern slopes drain into

Lake Elsinore Lake Elsinore is a natural freshwater lake in Riverside County, California, located east of the Santa Ana Mountains and fed by the San Jacinto River. Originally named ''Laguna Grande'' by Spanish explorers, it was renamed for the town of Elsino ...

(tributary to the

Santa Ana River The Santa Ana River is the largest river entirely within Southern California in the United States. It rises in the San Bernardino Mountains and flows for most of its length through San Bernardino and Riverside Counties, before cutting through ...

), except on the far southeastern ridge, where they are tributary to

Murrieta Creek Murrieta Creek runs southeasterly through southwestern Riverside County, California, United States, through the cities of Wildomar, Murrieta, and Temecula, ending southeast of the city center of Temecula, where it has its confluence with Temecul ...

, a tributary of the

Santa Margarita River The Santa Margarita River which with the addition of what is now Temecula Creek, was formerly known as the Temecula River, is a short intermittent river on the Pacific coast of southern California in the United States, approximately U.S. Geologi ...

.USGS Map Name: Sitton Peak, CA, from topoquest.com accessed on 4/16/2013
/ref>

References

{{Inland Empire Mountain ranges of Riverside County, California Peninsular Ranges Santa Ana Mountains Cleveland National Forest