The Epsom Salts Monorail (also known as the Magnesium Monorail) was a short-lived but remarkable engineering experiment in the remote Mojave Desert of San Bernardino County, California.
It operated as a Lartigue-type monorail from 1924 to 1926, spanning approximately 28 miles (45 km) to transport epsomite (hydrated magnesium sulfate, commonly called Epsom salts) from a deposit in the Owlshead Mountains (near the Crystal Hills and southern edge of Death Valley) to a siding on the Trona Railway at Magnesia (about six miles south of Trona, near Searles Lake).
This was one of the few commercial monorails ever built in the United States and briefly gained fame as the “fastest monorail in the world” due to its downhill speeds. However, it proved economically unviable and was abandoned after just two years of operation.
Discovery and Early Development (1917–1922)
In 1917, prospectors discovered a deposit of magnesium salts in the multicolored badlands of the Crystal Hills, a rugged area of low ridges and ravines in northwestern San Bernardino County, roughly 28 miles east of Searles Lake and near the old Wingate Wash Borax Road. The site lay in desolate desert terrain between Wingate Valley, the Panamint Range, and areas visible from Death Valley—virtually uninhabited and far from infrastructure.
Los Angeles florist Thomas Wright acquired the mining claims in 1919. Initially, he and his team hauled supplies over punishing 40–63-mile dirt tracks from Randsburg (a journey plagued by broken springs, overheating engines, and rough terrain). Wright envisioned exploiting the epsomite for pharmaceutical and industrial uses but faced major transport challenges.
A plan to dissolve the salts and pump them via a 28-mile pipeline to the Trona Railway was abandoned due to insufficient water. Traditional narrow-gauge rail or road grading proved prohibitively expensive in the steep, rocky canyons and unstable lake beds. In 1921–1922, Wright formed the American Magnesium Company and opted for a monorail system—specifically an adaptation of the French Lartigue monorail design, which used a single elevated rail and balancing outriggers for stability in challenging terrain.
Construction began in late 1922 at Magnesia Siding on the Trona Railway. Douglas fir timber was shipped by sea to San Pedro, then railed to the site. A prototype was built, and a patent secured on June 23, 1923.
Engineering and Construction (1922–1924)
The monorail was a custom timber-and-steel adaptation of the Lartigue system. A central 4×6-inch or 6×8-inch wooden “riding beam” (supported by A-frame trestles spaced about 8 feet apart) carried a standard T-section steel rail (mostly 80 lb/yd, some lighter). The A-frames featured diagonal braces, horizontal crosspieces, and 2×6-inch side balancing boards or rails for stabilizing rollers. Bents were anchored to broad sills sunk into sand and gravel, with extra bracing over arroyos. The entire structure rose only a few feet off the ground in most places.
The route climbed dramatically: it crossed the dry bed of Searles Lake in long tangents, ascended through Layton Canyon in the Slate Range (gaining 1,800 feet over 5 miles at a 7% grade), crossed Layton Pass (summit ~3,501 ft / 1,067 m), descended into Panamint Valley (with one road overpass creating a roller-coaster effect), climbed steeply (10–12% grades) over Wingate Pass, and followed Wingate Wash and Crystal Hills Wash to the mine. Blasting was required in hard-rock sections.
Construction took two years and cost an estimated $200,000–$350,000 (sources vary on the exact figure). By September 1923, half the line was complete. The monorail opened in June 1924.
Operation and Brief Success (1924–1926)
Rolling stock consisted of steel-framed locomotives and carriages with double-flanged wheels riding the central rail and spring-suspended steel rollers (8 inches high and wide) on the side boards for balance. Loads hung low in saddlebag-like containers on either side, keeping the center of gravity stable (much like pack saddles on a mule). Couplings came from scrapped Los Angeles streetcars. Brakes were locomotive-only.
Initially battery-powered units proved underpowered; the company modified seven Fordson tractors and one heavier Buda tractor into articulated monorail locomotives (each handling 1–2 trailers, or up to 3,400 lb per loco and 8,500 lb per car). A small workforce (12–15 men at the mine) scraped high-grade epsomite from surface deposits using basic tools.
Trains operated at normal speeds of 8–15 mph uphill/flats but reached up to 35 mph (56 km/h) downhill. One engineer famously completed a fully loaded 28–30-mile run in about one hour, earning the line its “fastest monorail in the world” nickname (though he was reportedly fired for the reckless speed). Salt was sacked at the mine, railed to Magnesia Siding, then shipped by standard rail to a refining plant in Wilmington, California, for processing into Epsom salts, Glauber’s salt, and magnesium carbonate.
Challenges, Decline, and Closure
Despite the engineering novelty, the operation faced insurmountable problems. High-grade surface epsomite depleted quickly, leaving lower-quality ore contaminated with up to 50% sand, clay, and other salts. Wooden beams warped as they dried in the desert heat, causing misalignment. Cloudbursts and flash floods washed out sections (especially near Layton Pass and on Searles Lake bed, where up to 14 inches of water softened sediments). Landslides and uneven settling further damaged the track. Locomotives and brakes were inadequate for sustained heavy loads, and maintenance was costly.
Output fell far short of estimates. Intense competition from cheaper brine-based magnesium producers doomed the venture. The mine and monorail shut down in June 1926 (some accounts cite 1927), after transporting only modest tonnages over two years. The American Magnesium Company was liquidated with minimal recovery of investment.
Aftermath and Legacy (1930s–Present)
The monorail stood idle for about a decade. In the late 1930s, the steel rail and longitudinal timbers were salvaged and sold for scrap. Only scattered A-frames remained, many later used as firewood, removed, or scattered by floods; most have since disappeared.
Today, the largest surviving sections lie in restricted military areas of the China Lake Naval Air Weapons Center (Range B). The mine site itself is within Death Valley National Park and accessible via Fort Irwin National Training Center near Tecopa (with permits). Concrete foundations, salt piles, and house ruins persist at the old camp. A historical marker (erected 2008 by E Clampus Vitus and the Bureau of Land Management) stands near SR-178 and Pinnacle Road, about 16 miles east of Ridgecrest.
The Epsom Salts Monorail remains a classic example of desert mining ambition and engineering ingenuity in the face of harsh geography. It highlighted the limits of wooden infrastructure in extreme environments and the economic realities of remote mineral extraction. Though a commercial failure, its innovative design and brief “world’s fastest” reputation continue to fascinate historians of unusual railways.
For further reading, see Alexander K. Rogers’ book The Epsom Salts Monorail: The American Magnesium Company Monorail in San Bernardino County, California (Maturango Museum) and Richard H. Jahns’ 1951 article “Epsom Salts Line—Monorail to Nowhere” in Engineering and Science.