Mountain Pass is an

unincorporated community An unincorporated area is a parcel of land that is not governed by a local general-purpose municipal corporation. (At p. 178.) They may be governed or serviced by an encompassing unit (such as a county) or another branch of the state (such as th ...

San Bernardino County San Bernardino County ( ), officially the County of San Bernardino and sometimes abbreviated as S.B. County, is a county located in the southern portion of the U.S. state of California, and is located within the Inland Empire area. As of th ...

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

, United States. It is situated on

Interstate 15 Interstate 15 (I-15) is a major Interstate Highway in the Western United States, running through Southern California and the Intermountain West. I-15 begins near the Mexican border in San Diego County and stretches north to Alberta, Ca ...

in the southeast mountainous desert region of the state approximately from the

Nevada Nevada ( ; ) is a landlocked state in the Western United States. It borders Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the seventh-most extensive, th ...

border at an elevation of —the highest point along I-15 between California and Nevada. It has a population of 30. The most prominent feature of the town, and its reason for existence, is the Mountain Pass Mine, an open pit mine for

rare-earth element The rare-earth elements (REE), also called the rare-earth metals or rare earths, and sometimes the lanthanides or lanthanoids (although scandium and yttrium, which do not belong to this series, are usually included as rare earths), are a set o ...

s. The mine and its associated processing facilities are owned by MP Materials, which purchased the assets out of bankruptcy on July 10, 2017. It produces approximately 15% of rare metals in the world.

Climate

Typical of the High Desert, Mountain Pass has a cold semi-arid climate (

Köppen climate classification The Köppen climate classification divides Earth climates into five main climate groups, with each group being divided based on patterns of seasonal precipitation and temperature. The five main groups are ''A'' (tropical), ''B'' (arid), ''C'' (te ...

''BSk''), Winters are chilly but also sunny, with daytime highs around 50 and nighttime lows just below freezing. Summers are hot and somewhat wetter, with July, the hottest month, having a normal high in the low 90s. Although dry weather usually prevails in most months, the wettest months are July and August when thunderstorms commonly form over the nearby mountain ranges, which can cause flash flooding. Snow is rare but not uncommon, usually falling 2-3 times a year. Most of the snow doesn't stick to the ground very long, usually melting by mid afternoon.

References

{{authority control Geology of California Unincorporated communities in California Unincorporated communities in San Bernardino County, California