There are only two feasible railroad routes north from the Los Angeles Basin—Soledad Canyon from Saugus to Palmdale and Cajon Pass from San Bernardino to Victorville. Southern Pacific used the Soledad Canyon route for its 1870s entry to Los Angeles from the north. When Santa Fe interests needed a way into the Los Angeles basin from the Barstow area in the 1880s, Cajon Pass was selected, not only because the Soledad Canyon route was already taken, but also because the first line projected south from Barstow was headed for San Diego (as the “California Southern”), not Los Angeles. The lines towards Los Angeles were built later and the original line to San Diego abandoned after several washouts in Temecula Canyon a few years after that. In the late 1960s, Southern Pacific needed a way to bypass traffic congestion on its lines in Los Angeles, and built a line from the Sunset Route at West Colton to the Tehachapi line at Palmdale, over Cajon Pass. This line became known as the “Palmdale Cutoff”.
Cajon Pass exists because the San Andreas earthquake fault runs east-southeast to west-northwest through this area (and is also responsible for the Beaumont/Banning pass to the east). The fault passes just to the north of San Bernardino (at the base of the San Bernardino Mountains), and the resulting cleft in the mountains (between the San Bernardino Mountains to the east and the San Gabriel Mountains to the west) runs in a northwesterly direction from San Bernardino until it reaches the 3000 ft. level, at which the route to the summit turns north and then east in a vast bowl among mountain peaks in all directions. Cajon Creek runs along the bottom of the northwesterly cleft in the lower regions of the pass. Today, the BNSF (ex-Santa Fe) tracks and the UP (ex-SP) track are joined by Interstate 15 and the various remnants of old US 66 in traversing Cajon Pass.
The former Southern Pacific line over Cajon Pass (the “Colton-Palmdale Cutoff”) comprises the following subdivision:
The south end of the Palmdale Cutoff is at Rancho (MP 492.7 directly from the north, MP 538.5 on the Sunset Route, elevation 988 ft.), at the east end of West Colton Yard some 4 miles or so east of the West Colton mile marker. The junction with the Sunset Route is a wye, permitting direct access both to West Colton Yard and the Sunset Route to the east. The west side of the wye is adjacent to the balloon track at the east end of West Colton Yard. The other end of the wye is at East Wye-Bypass (MP 492.6, el. 996 ft.). Track speed through the wye is 15 mph. Immediately north of the wye, the Palmdale Cutoff crosses the wye-bypass on an overbridge and passes over both Interstate 10 and Valley Boulevard. Not far north of the wye (and just north of Valley Boulevard) is the 9127 ft. siding at Slover, from MP 491.9, el. 1,050 ft., to MP 490.0, el. 1,178 ft. The signals at the north end of the wye also seem to serve as the south facing signals for the south end of Slover siding. There are, of course, north facing signals governing southward exit from that siding, having two searchlight-style signals mounted one above the other on the same post.
The track in this area is oriented almost due north-south (with higher mileposts to the south). Track speeds on the cutoff itself are 35 mph for freight and 50 mph for any passenger train that may happen to run here (none are, or even have been, scheduled). There are bridges over city streets at C Street and Olive Avenue along the siding. Before reaching the north end of the siding, there is a bridge under Mill Street. At the north end, there are southward facing searchlight signals governing the northbound exits from, and a north facing searchlight signal governing entry to, the siding or main track. The switch at the north end of Slover is a hand-throw switch only. At Rialto Avenue, beyond the siding’s north end, the line crosses both the street and the Metrolink line (former Santa Fe Pasadena Subdivision) on an overbridge and then connects with the former Pacific Electric San Bernardino line (now owned also by Metrolink) at Bench (MP 489.8, el. 1,198 ft.), providing access to spurs for Orange County Lumber and Southern California Edision. There are intermediate searchlight signals at Bench, between Rialto and Baseline, facing both ways, and Foothill Boulevard crosses overhead.
North of this location, the line curves gently NNE into the Lytle Creek flood control basin, heads along the west side of the Lytle Creek wash in a NNW direction, crossing under Baseline Road, then turns NNE again to cross Lytle Creek, crossing I-210 and Highland Avenue on an overbridge before turning NNW again. Curving north around a housing area to the east, the line approaches Cajon Boulevard from the west, crossing Institution Road on an overbridge. There is a detector at MP 486.8, intermediate signals, formerly at MP 486.5, of the searchlight form, facing each way, now (April, 2011) at MP 485.9, of the two-headed ‘hooded’ form, facing each way and MP 483.5. There is a 7700 ft. siding at Dike, from MP 481.8, el. 1,900 ft., to MP 480.2, el. 2,022 ft., along which the line comes alongside (and to the west of) the BNSF Cajon Pass line. The south end of Dike has a two-headed signal facing south on the single track and two searchlights facing north, one on each track. The north end of Dike has searchlights facing south, one for each track, and a two-headed signal facing north.
The Palmdale Cutoff runs generally just to the west of the BNSF line, with some local variations for topography, all the way to the top of the pass and a little beyond. The south end of the interconnection to the BNSF line is at MP 479.0, el. 2,108 ft. and has a two-headed signal governing exit from the interconnector. There are searchlight-style intermediate signals at MP 476.7, facing each way. There is a detector on the Palmdale Cutoff at MP 475.1, where there are also two-headed intermediate signals facing each way. As the line turns ENE near Blue Cut, it separates a little from the BNSF, crosses a side stream on a medium fill, and crosses Swarthout Canyon Road at grade, almost directly above Blue Cut. There are Intermediate Signals at MP 473.3, and at MP 472.2, there are intermediate signals with two heads facing each way plus an additional lower-level signal head facing south only.
Before reaching the BNSF Cajon location, the ex-SP line is already curving away to the NNW and then directly west to stay west of the BNSF track 1 as the latter negotiates Sullivan’s Curve. While on the westerly heading, the south end of Canyon Siding, MP 471.3, el. 2,982 ft., is reached. This 9,515 ft. siding and its main track curves along with the BNSF track 1 until the latter curves away under Route 138, where the north end of the ex-SP Canyon siding is reached at MP 469.3, el. 3,226 ft. This lines crosses Route 138 on an overbridge, not far west of the BNSF track 1 underbridge, passes in front of Mormon Rocks (i.e. to their east), crossing over Cajon Creek on a bridge in the process, then follows BNSF track 1 around to the east, under Interstate 15 and across Baldy Mesa Road on an overbridge just north of the BNSF Alray location. Continuing alongside BNSF track 1, just slightly further up the hillside, the ex-SP line passes through cuts adjacent to the two BNSF tunnels.
Further east, the line turns southeast as it reaches the “south” end of the Silverwood interconnection (MP 464.7, el. 3,744 ft.), then turns east through a fairly deep cut as it reaches the summit of the line (3,850 ft. in altitude, somewhat higher than the BNSF summit) at the ‘south’ end of Hiland siding (MP 463.8, el. 3,848 ft.), where there are two separate searchlight signals on the same post, facing south, and two single searchlights, one for each track, facing north and governing the exits from each track. This 9,097 ft. siding extends well to the east of the summit area, curving back and forth along the northwest edge of the Summit Valley, now in cuttings, now on fill with views down to the BNSF line and gradually edging further away from the latter under the high voltage power lines, until, beyond the ‘north’ end of Hiland (at MP 461.9, el. 3,849 ft., with the usual complement of signals), the former curves away through a deep cutting north past a gated (and locked) dirt road crossing at Amstoy Road, then past the Southern California Edison spur to the northeast at Hivolt (MP 460.0, el. 3,839 ft.), and then turns northwest across the Ranchero Road, Hesperia, grade crossing and under I-15 to head for Palmdale.
At this location, I-15 is running north-northeasterly along the top of a ridge, so the rail line easily passes underneath it and the adjacent (on the east side) frontage road, Mariposa Road, passes a detector at MP 457.9, an intermediate signal at MP 457.2 and crosses a valley on a high fill to reach the end of Belleflower Street, Hesperia, than enters another cutting on the west side of that valley. West (“north”) of that cutting, the line passes under several more high voltage power lines in the Power Line Road area, and then emerges onto the high desert for a gradual descent of over 1,000 ft, heading in a generally west-northwesterly direction all the way to Palmdale.
There are intermediate signals at MP 454.8, where the line crosses Baldy Mesa Road at grade. The line then crosses Phelan Road at grade (MP 453.7), curves to the west-northwest and crosses Caughlin Road at grade. Just west of that grade crossing is the east (“south”) end of Phelan siding (MP 451.9, el. 3,720 ft.), also with the usual complement of signals. The west (“north’) end of Phelan siding is at MP 450.1, el. 3,650 ft., followed by grade crossings of Wilson Ranch Road, Duncan Road, and Johnson Road. There are intermediate signals at MP 447.7, a grade crossing at Sheep Creek Road, a detector at MP 446.6, more intermediate signals at MP 445.4, and a grade crossing at Beekly Road. After the line crosses the California Aqueduct, there are intermediate signals at MP 442.2, and a grade crossing at Oasis Road. Palmdale Boulevard (Route 18) passes overhead on a concrete bridge; there are intermediate signals at MP 438.25, a grade crossing of an unidentified dirt road and one of Black Butte Road, MP 436.4, before reaching the east (“south”) end of Wash siding at MP 436.1, el. 3,200 ft., which has the usual complement of signals. Nearing the west (“north”) end of Wash, which is at MP 434.25, el. 3,130 ft., there is a setout spur on the south (“west”) side of the tracks.
There is a detector at MP 431.1, followed immediately by the grade crossing at 165th Street East (in Los Angeles County’s Antelope Valley), MP 431, culverts for another wash at MP 427.75 or thereabouts, intermediate signals at MP 426.0, and grade crossings at 116th Street East and 106th Street East. Avenue T (in Los Angeles County’s Antelope Valley) crosses the line on a concrete bridge, after which 96th Street East crosses at grade, as does 94th Street east at a private crossing. There are intermediate signals at MP 423.4, and a grade crossing at 92nd Street East, after which the line passes a spur on the south side for Holiday Sand & Gravel, bridges over 87th Street East, Little Rock Wash and another wash, and Fort Tejon Road, all using through girder bridges.
There is a grade crossing at 47th Street East, Palmdale (MP 418.8), and another at 40th Street East before reaching the east (“south”) end of Palmdale siding at MP 418.1, el. 2,732 ft. There is a bridge over 25th Street East, the west (“north”) end of Palmdale siding (MP 416.5, el. 2,726 ft.), a private grade crossing at Desert Lawn Memorial Park; Avenue S bridges over the track and there is a grade crossing at 10th Street East and a bridge over Sierra Highway before the line reaches Palmdale Junction (MP 414.4 el. 2,657 ft.) and comes alongside the Metrolink line on the east side of the latter as both continue due north. From here north to Lancaster Metrolink constructed a parallel track (with concrete ties) in 1994 on a separate strip of the right of way that was purchased in 1992. This line was very easy to design, the contractor was simply told to build the new track 20 feet west of the SP track and at the same elevation, no blueprints needed! (Grade crossings did require considerable engineering to sort out the utilities and street alignment for the second track.)
Metrolink’s CP Harold is the location of a crossover from the Metrolink line to Palmdale Junction (MP 414.4, el. 2,657 ft.) on the UP line, the only connection between the two adjacent parallel lines, which share road crossings and bridges between this location and Lancaster Boulevard. There is a grade crossing at Avenue R. The faded blue building on the east side of the tracks is the UP Roadmaster’s office where it is common to see carloads of company material on the nearby spur track. Next the line crosses Palmdale Blvd, and City Hall is visible to the east. To the west is a drainage ditch that Metrolink had to move to construct the new track in 1994, followed by the site of the new (2005) Palmdale Station. North of the construction site Sierra Highway crosses the tracks at grade to attain their west side, and continues running parallel to them thereafter. There are signals on the UP line at the Sierra Highway crossing, a spur on the east side for Terry Lumber Company, and a detector at MP 412.6.
Rancho Vista Boulevard (formerly Avenue P) crosses at grade at MP 412.2. There are Metrolink signals at MP 71, with UP signals adjacent to their east. Between mileposts 71 and 72, Air Force Plant 42 dominates the view to the east, first with large assembly buildings, then with an enormous runway. This is where the B-2 bombers were assembled and made their test flights. A quick look around these buildings may reveal NASA U-2s or other exotic aircraft. There are spurs on the east side for Lockheed, both directly from the main line and from Denis Siding. At MP 410.9 on the UP line, 8,350 ft. Denis siding begins, and at MP 409.2 (el. 2,549 ft.) the siding ends, just south of the Columbia Way road crossing. There are Metrolink signals just north of that road crossing.
Avenue L crosses over both the lines and Sierra Highway on a bridge. There are Metrolink signals at CP Bonita (MP 75.0), a grade crossing at Avenue K, spurs on the east side for Terry Lumber and Antelope Valley Distributors, UP signals at MP 406.1 (named “[South] Lancaster”), Avenue J crosses the lines at grade; there are Metrolink signals and switches at CP Sierra (MP 76.1), to a single storage track. The Metrolink line enters the Lancaster Metrolink station at MP 76.6, with depot and parking lot to the west of the tracks (and the east side of Sierra Highway). This depot is also the local Greyhound terminal. The Metrolink line ends at buffer posts on both platform line and adjacent siding immediately south of the Lancaster Boulevard grade crossing on the still adjacent UP line which continues northward alone, with the Lancaster siding, the Lancaster Team Track, and spurs for Endura Steel Company, Victor Rycke Bosch Inc., and WA Thompson Distributors, to the east.
Sierra Highway continues to run alongside the line on its west side almost all the way to Mojave. There is a grade crossing at Avenue E, signals at MP 404.3 (el. 2,355 ft.), [North] Lancaster, a bridge over the track at Avenue H, and a grade crossing at Avenue G, adjacent to intermediate signals at MP 403.1. After the grade crossing at Avenue E comes the south end of Oban siding (MP 401.0), followed by the north end of Oban (MP 399.3, el. 2,299 ft.). There are many bridges over drainage along this section of the line. There is a grade crossing at Avenue C, a car identification scanner at MP 398, intermediate signals at MP 397.3, a grade crossing at Avenue A (where the lines enters Kern County), a detector at MP 396.1, and more intermediate signals at MP 395.3.
There are spurs on the east (Great Lakes Carbon and San Luis Butane) and west sides of the line (Rosamond Storage) at Rosamond (MP 394.3, el. 2,322 ft.), a grade crossing at Rosamond Boulevard, intermediate signals at MP 393.1, the south end of Ansel siding at MP 391.1 (el. 2,534 ft.) and its north end at MP 389.5, Sopp Road grade crossing at MP 388.7, and intermediate signals at MP 387.3 and 385.7. There is a siding at Fleta (MP 384.4, el. 2,637 ft.), between hand-throw switches at MP 385.7 and MP 383.5, with more intermediate signals at the latter, and spurs on the east side for Ashland Chemical, Courtaulds Aerospace, Purdy Company and US Borax, to the east. There is a grade crossing at Purdy Road (MP 382.6), followed by the Tosco oil tank car terminal and spurs heading eastward (Nixlor Chemical Company) at South Mojave before the BNSF Mojave Subdivision line from the east trails in right under the highway 14 overbridge at South Mojave, MP 381.3.