This route covers the following subdivisions:
The Metrolink San Gabriel Subdivision runs from downtown Los Angeles east to San Bernardino, using tracks formerly owned by Pacific Electric, Southern Pacific, and Santa Fe. It starts at Control Point (CP) Pasadena Junction, MP 0.9 (from Union Station) on the East Bank line of the Metrolink River Subdivision along the Los Angeles River, adjacent to the southwest corner of Union Pacific's former Southern Pacific yard, just east of downtown Los Angeles. Centralized Traffic Control (CTC) from the Metrolink Dispatching Center in north Pomona governs the entire line, which is mostly laid with 119 lb. rail. The line, initially heading south at the junction, turns away to the east, passes under Mission Road, and emerges, two tracks wide, alongside and to the north of Interstate-10, the San Bernardino Freeway. The right-of-way here was once the main eastern route of the Pacific Electric interurban line, four tracks wide, that emerged from the center of Los Angeles and crossed to river along the route now occupied by the freeway. The PE lines to the east of the river at this point closed when the route was condemned by eminent domain proceedings, for the purpose of building the (then) Ramona Freeway in 1951.
Just across the river from the gleaming high-rise buildings of downtown Los Angeles, the area between the river and the Golden State Freeway (Interstate-5) comprises many ramshackle rundown buildings, signed completely in Spanish, reminiscent of the poorer areas of Tijuana, across the Mexican border to the south. The railroad parallels I-10 as it passes under I-5 heading east and climbing steadily, and comes alongside the hill on which Los Angeles County-USC General Hospital is located. As it passes under the intersection of Marengo Street and Soto Street on the southeast edge of the hill, the right of way of the former PE line to Pasadena and the west San Gabriel Valley curves away to the northeast at what is now CP Marengo (MP 2.4). Still clearly visible, this r-o-w was once home to a parade of interurban trains bringing the residents of Pasadena, Sierra Madre, Arcadia and San Gabriel downtown, and visitors to Santa Anita Racetrack and the Pasadena Tournament of Roses in the opposite direction. Today's San Gabriel Subdivision continues along the former right-of-way of the PE line that went all the way to San Bernardino along the Ramona Boulevard corridor.
Passing under a bridge carrying Charlotte Street, the line, now a single track, comes alongside one of the city's municipal housing projects. A pedestrian bridge crosses the line and freeway, and then a road bridge carrying Herbert Avenue. Heading east-northeast, now, the line passes under Eastern Avenue and then Campus Drive to reach its first station at California State University, Los Angeles (Cal State LA) at MP 4.6. At this point, the busway built along the San Bernardino Freeway also has a station, located directly above the Metrolink station, with the busway bridges (viaducts) snaking above the railroad tracks. The station comprises an island platform between the main track and a siding at this location. (The station entrance is at a yet higher level, adjacent to the lowest level of the university buildings located atop an adjacent hill.) East of their respective stations here, the line and the busway negotiate the bridges carrying I-710 (the Long Beach freeway) and a plethora of interchange ramps, and cross over the westbound lanes on a bridge to enter the median of the San Bernardino freeway, at this point heading northeast but soon to curve to the east.
In the center of the freeway, the single-track railroad line passes over the many streets and occasional stream crossed by the freeway, but there are no separate bridges for the railroad at any of these locations with the roads and streams being unnoticeable from the perspective of the railroad. The occasional footbridge and road bridge crossing overhead similarly have no independent existence from the railroad's perspective. There are several sets of signals located along the railroad on this segment, two sets for the siding between CP Fremont (MP 6.0) and CP Marguerita (MP 6.3), somewhat east of the Almansor Avenue overbridge and one set between that bridge and the San Gabriel Boulevard busway entrance ramps to its east. The freeway, busway and railroad complex passes through a largely residential section of the west Sam Gabriel valley, with the housing areas in Alhambra, San Gabriel and Rosemead variously populated, in 2004, by a mix of Hispanic and Asian ethnic groups, in housing stock dating largely from (approximately) the 1950s and 1960s. The line here approximately follows the route of the old PE San Bernardino line, which ran along the old Ramona Boulevard in the area now occupied by the freeway.
At the eastern edge of Rosemead, where the freeway angles south-southeast for a short distance, the railroad exits the freeway median via a tunnel under the westbound lanes, emerging onto a viaduct that crosses the Rio Hondo to enter El Monte, turns north northeast on its east bank (past the El Monte bus station that is the destination of the busway), crosses over Valley Boulevard, turns to the southeast while crossing over Santa Anita Avenue, and descends alongside and to the south of the former Southern Pacific "Sunset Route" line (now the Union Pacific Alhambra Subdivision) to reach the Metrolink El Monte station (MP 12.6). The station is again an island platform between the main track and a siding, with signals at the west end of the station (CP Hondo, MP 12.5) governing the west end of the siding. The parking area is to the south of the station, whose platform has several waiting areas roofed with red tile, each topped by the metal silhouettes of several lions (papa, mama and two cubs) performing a “lion-tamer act”. The scenes are different on each roof'.
The line continues southeastward through this mixed residential and commercial area with grade crossing at Tyler Avenue, Cypress Avenue, Ramona Boulevard and Peck Road. There are signals between Tyler and Cypress Avenues (CP Ramona, MP 13.0) as the line returns to single track. The line passes under I-10 and then crosses Cogswell road at grade. It passes over Garvey Avenue on a bridge, and over Durfee Road on another. As it reaches the San Gabriel River, the Metrolink line rises on a viaduct and crosses over the Sunset Route, descending on the north side of the latter to pass under I-605 at the same grade as that line. There are signals at this location (CP Bassett, MP 15.3) as the line again acquires a siding, this time on the north side, extending around the bend to CP Amar (MP 16.5). There are interconnections with the Sunset Route along the stretch where the lines run parallel to one another. After crossing Temple Street at grade alongside the Sunset Route, the Metrolink line turns northeast, east of Baldwin Park Boulevard, and shortly crosses Temple Avenue (which has made a right-angle turn in the meantime) at grade, again. This segment of the line was formerly part of the Southern Pacific's Azusa Branch. An industrial area in Bassett at the southwestern end of this segment gives way to a residential area in Baldwin Park.
The line crosses Amar Road at grade, Walnut Creek on a bridge and Dalewood Avenue at grade before passing under I-10 again. It crosses Francisquito Avenue at grade, a pedestrian grade crossing at the end of Foster Avenue, passes signals at MP 18.1, crosses Merced Avenue at grade and Pacific Avenue at grade before reaching the Cruz Baca Transportation Center at Baldwin Park (MP 18.8), a single platform on the southeast side of the track (with adjacent parking lot to the southeast) followed by another grade crossing of Ramona Boulevard, after which the line curves from northeast to east, passes signals at MP 19.1, and crosses the Dalton Wash before reaching the grade crossing of Azusa Canyon Road. Just east of Azusa Canyon Road is Orange Avenue Junction, MP 19.9, where the Azusa Industrial Track (the remainder of the former SP branch) curves away to the north; the line now takes over the route of the former SP San Dimas branch. As the line curves from northeast to east, it now parallels the route of the PE San Bernardino Line, which had followed the alignment of Ramona Boulevard all the way from the exit from the San Bernardino Freeway median to this location and continues to follow Ramona Boulevard further east.
The line now passes through residential suburbs, from the 1960s and after, for the entire way to Pomona. Having dropped in height through the west San Gabriel Valley, from Cal State LA to Rio Hondo, the line now rises through the east San Gabriel Valley as it continues eastward, crossing Irwindale Avenue, Vincent Avenue, Lark Ellen Avenue, Azusa Avenue, Hellman Avenue and Citrus Avenue at grade. There are signals at MP 21, between Lark Ellen and Azusa Avenues, and lineside industry along the north side of the track through this area. The Covina Metrolink station (MP 23.0) is on the both sides of the line, which has two tracks and two platforms at this point (extending from CP Irwin, MP 20.4 to CP Barranca), east of Citrus Avenue, with an adjacent “permit only” parking area on the north side. General parking is available on the south side of the tracks, on the west side of Citrus Avenue. There are signals just to the east of the station (CP Barranca, MP 23.4).
East of the Covina station, the lines crosses Barranca Avenue, Grand Avenue, Glendora Avenue and Cypress Street at grade, there are signals at MP 24.1, and the lines crosses Bonnie Cove Avenue, Covina Avenue, Sunflower Avenue, Valley Center Boulevard and Lone Hill Avenue at grade. Lineside properties throughout this region are mainly residential, with city parks and school buildings and playing fields for variety. East of Lone Hill Avenue, the line passes under route 57 (a freeway, once numbered I-210 at this point). At Cataract Avenue there is a spur to lineside industry as well as a road crossing at grade. Running just to the south of Arrow Highway, the line crosses San Dimas Avenue, Walnut Avenue, San Dimas Canyon Road, Gainey Ceramics private road, and Wheeler Ave. (next to the furthest east UP industry, a bulk plastics facility) and Fairplex Drive. The latter is adjacent to the Pomona Fairplex grounds, next to the drag racing track and stands.
The line then angles north, crossing Arrow Highway at grade, angles east again, alongside the former Santa Fe Pasadena subdivision to the north of the Metrolink line, crosses White Avenue, passes signals at CP White (MP 30.3), and Fulton Avenue, and enters the Pomona Metrolink station. This is an island platform between the two main tracks that run between CP White and CP Central (MP 34.6), and has a parking area to the north accessed by means of a grade crossing at the east end of the platforms. The Metrolink Operations Center or MOC (the dispatching office) is just south of the station. At Garey Avenue, crossed at grade, the former Santa Fe Pomona depot, once used by Amtrak, lies on the north side of the Metrolink line and the south side of the former Santa Fe line (now the Metrolink Pasadena subdivision). This building is now used as a base by Metrolink’s Maintenance Department and by maintenance contractor Herzog. After crossing Towne Avenue at grade, the former Santa Fe line and the more northerly of the Metrolink tracks (track 1) join at CP Cambridge (MP 32.4), while track 2 (on the south side) continues straight through. The tracks cross Cambridge Avenue and Indian Hill Avenue at grade, pass a hotbox detector at MP 32.9, and reach the delightful station in Claremont (MP 33.0), an erstwhile Santa Fe facility maintained in lovely condition, with Metrolink platforms on both tracks at this point. There is a parking garage east of the station and a large parking lot east of College Avenue, both on the north side of the tracks. At this point, the right-of-way of the former PE line diverges to the north and the present-day line continues east on the former Santa Fe routing. Claremont is a lovely old college town (the “Claremont Colleges”), in great contrast to the gritty urban surroundings of Pomona just to the west. At both Claremont and Montclair, where the main station facilities are on the north side of the line, westbound trains use the platform on the north side unless an eastbound train is due at the same time as their station call.
East of Claremont station, the line crosses College Street and Claremont Avenue at grade, passes the signals at CP Vista (MP 34.0), where there is a left hand crossover (only), crosses over Monte Vista Avenue on a bridge built in 1993, after Metrolink took over the track and started running passenger services on this line (October, 1992), and enters the Montclair Metrolink station, again with platforms on both sides of the tracks adjacent to a large parking lot on the north side. East of Montclair, the lines reaches CP Central, MP 34.6, where it reverts to single track, crosses Central Avenue, Benson Avenue, Mountain Avenue and San Antonio Road at grade, passes signals at MP 35.1, crosses Euclid Avenue and Second Avenue at grade and enters Upland Metrolink station (MP 36.9), where the former Santa Fe depot on the north side of the track is intact but currently unused. The platform shelters at Upland have red tile roofs.
The line then crosses Campus Avenue, Grove Avenue, Baker Avenue, and Vineyard Avenues at grade, crosses over Cucamonga Creek, and crosses (another) Hellman Avenue and Archibald Avenue at grade. East of Archibald Avenue is CP Archibald (MP 40.2), after which the lines crosses Hermosa Avenue at grade, throws off an east-facing spur to the south, crosses Haven Avenue at grade and reaches the Ranch Cucamonga Metrolink station (MP 42.0) Here the platform is on the south side of the more southerly of the two tracks at this point, with a wye to the north reaching lineside industries. There is a large parking lot to the south of the station, adjacent to vast new construction of apartment buildings. The whole area east of Claremont is filled with new residential construction, most of it post-dating the availability of Metrolink train services into Los Angeles. Access to the wye tracks is controlled from CP Rochester (MP 42.3), just west of the Rancho Cucamonga station and the bridge over Milliken Avenue, where there are other lineside industries extending from Milliken Avenue. Rochester Avenue is crossed at grade, and the line then passes underneath I-15.
East of I-15, there are now two main tracks from CP Nolan (MP 44.5) to CP Beech (MP 47.6), track 1 on the north side and track 2 to its south. There is another spur to lineside industry on the north side of the track at Etiwanda Avenue, site of another at grade road crossing. East of Etiwanda Avenue, where the Kaiser steel mill used to be, the California Speedway now occupies the south side of the tracks. Calabash Avenue crosses the tracks (at a non-public grade crossing) at this location. There is an occasional-use Metrolink station here (CP Speedway, MP 45.3), an island platform in between the two main tracks, along with some storage tracks. Immediately east of this location is the BNSF Kaiser yard (CP Kaiser, MP 45.4), nominal destination of two daily switching turns out of San Bernardino, through which there is a third track, the “South Kaiser”. East of Speedway the line and yard passes under the Cherry Avenue bridge. East of the yard, the line crosses Beech Avenue at grade. There are signals and a lineside spur at CP Beech, MP 47.6, followed by the Citrus Avenue road crossing another hotbox detector (MP 48.8), Juniper Avenue, and the Fontana Metrolink station (MP 49.0). The latter has a platform on the north side of the track and a parking lot to the north of that.
East of the Fontana station, the line crosses Sierra Avenue, Mango Avenue, Palmetto Avenue, Alder Avenue and Locust Avenue at grade. There are large warehouses along the south side of the track between Fontana and Rialto. CP Locust (MP 50.7) is at the west end of a siding that extends to CP Lilac (MP 52.4). The signals for CP locust are east of Locust Avenue, after which the line crosses Cedar Avenue at grade. Cactus Avenue is crossed at grade, and there is a spur on the north side to grain silos just east of that crossing. The signals at CP Lilac are reached west of Lilac Avenue, which is crossed at grade. East of the Willow Avenue road crossing is the Rialto Metrolink station (MP 52.9), graced by an ornate depot building and parking lot on the north side of the track. The Rialto Depot building is named the ‘John Longville Depot’, for a local politician and SCRRA Board member, and houses a restaurant staff training facility that serves breakfasts and lunches to the public.
Riverside Avenue, Sycamore Avenue, Acacia Avenue, Eucalyptus Avenue and Pepper Avenue are crossed at grade before the line angles north to cross Rialto Avenue at the same spot at which it passes under the former SP Palmdale Cutoff line. The bridge crossed by the latter is longer than it apparently needed to be, because at the time of its construction there were proposals for a grade separation of the then Santa Fe line and Rialto Avenue which would have required more space under the then SP line. Angling east again, the line crosses Rancho Avenue at grade and then Lytle Creek on a bridge. Alongside the BNSF San Bernardino intermodal yard and locomotive facilities, on the south side of the line, the track rises on a flyover to cross the BNSF San Bernardino subdivision coming in from the south at CP Rancho (MP 55.3) and descends to pass under Mount Vernon Avenue and enter the Metrolink San Bernardino station and storage tracks at MP 56.2. These are adjacent to, and west of, the former Santa Fe depot at this location, long used by Amtrak. Two of the storage tracks are in the southeast corner of the curve onto the former Santa Fe ‘short way’ line towards Colton now use by weekend Metrolink trains between San Bernardino and Riverside Downtown.
Passenger service under Metrolink auspices started on October 26, 1992, and has grown to the 2004 level of 15 trains each way covering the entire line, and two short turns to Covina, on weekdays, eight trains each way on Saturdays, some of them extended to Riverside, and four trains each way on Sundays, some of them extended to Riverside. Amtrak's Sunset Limited (trains 1 and 2) also uses the Metrolink line between El Monte and Los Angeles, although without stopping at any Metrolink stations.
Union Pacific runs a peddler freight out of Bassett as far as Wheeler Avenue in Pomona, servicing lineside industries on the former SP segments of the line. BNSF runs switchers out of San Bernardino serving lineside industries on the former Santa Fe segments of the line as well as serving the still extant BNSF Kaiser Yard. In early 2004, BNSF is loading logs cut from the trees that died in the 2003 firestorms in the local mountains, for shipment to lumber mills in Northern California.
Apart from occasional diversions when adjacent lines are closed for some reason, there is no through freight service on this line.