The Pasadena Subdivision is the remnant branch line

Branch line

A branch line is a secondary railway line which branches off a more important through route, usually a main line. A very short branch line may be called a spur line...

 of the former Atchison, Topeka and Santa Fe Railway

Atchison, Topeka and Santa Fe Railway

The Atchison, Topeka and Santa Fe Railway , often abbreviated as Santa Fe, was one of the larger railroads in the United States. The company was first chartered in February 1859...

 Los Angeles Second District. Currently the line branches off of the Metrolink San Bernardino line at CP Cambridge in Claremont

Claremont, California

Claremont is a small affluent college town in eastern Los Angeles County, California, United States, about east of downtown Los Angeles at the base of the San Gabriel Mountains. The population as of the 2010 census is 34,926. Claremont is known for its seven higher-education institutions, its...

. The line follows a generally east-west alignment, passing through the cities of Claremont, Pomona

Pomona, California

-2010:The 2010 United States Census reported that Pomona had a population of 149,058, a slight decline from the 2000 census population. The population density was 6,491.2 people per square mile...

, La Verne

La Verne, California

La Verne is a city in Los Angeles County, California, United States. The population was 31,063 at the 2010 census, down from 31,638 at the 2000 census.-History:...

, San Dimas

San Dimas, California

San Dimas is a city located in the San Gabriel Valley, in Los Angeles County, California. As of the 2010 census, the city had a total population of 33,371. The city historically took its name from San Dismas Canyon in the San Gabriel Mountains above the northern section of present day San Dimas...

, Glendora

Glendora, California

Glendora is a municipality in Los Angeles County, California, United States, east of downtown Los Angeles. As of the 2010 census, the population of Glendora was 50,073....

, Azusa

Azusa, California

Azusa is a city in Los Angeles County, California, United States. The population was 46,361 at the 2010 census, up from 44,712 at the 2000 census. Though sometimes assumed to be a compaction of the phrase "everything from A to Z in the USA" from an old Jack Benny joke, the place name "Azusa"...

, Irwindale, Duarte

Duarte, California

Duarte is a city in Los Angeles County, California, United States. As of the 2010 census, the city population was 21,321, down from 21,486 at the 2000 census....

, and Monrovia

Monrovia, California

Monrovia is a city located in the foothills of the San Gabriel Mountains in the San Gabriel Valley of Los Angeles County, California, United States. The population was 36,590 at the 2010 census, down from 36,929 at the 2000 census...

 before coming to a truncated end in the city of Arcadia

Arcadia, California

Arcadia is an affluent city in Los Angeles County, California, United States, and located approximately northeast of downtown Los Angeles in the San Gabriel Valley and at the base of the San Gabriel Mountains....

.