History of Potash Production from the Salduro Salt Marsh (Bonneville Salt Flats), Tooele County

By J. Wallace Gwynn

The first 10 to 12 miles of Interstate 80 east of Wendover, Utah traverse the seemingly endless, flat, white, salt-covered expanse of the Bonneville Salt Flats, known in the early 1900s as the Salduro Salt Marsh. The salt flats and the surrounding Great Salt Lake Desert are remnants of the bed of an ancient, large, cyclic lake whose latest cycle, called the Lake Bonneville cycle, occurred from about 32,000 to 14,000 years ago. Lake Bonneville had a depth of more than 1,000 feet, and covered an area of 20,000 square miles in western Utah plus small portions of southern Idaho and eastern Nevada. Though the water of Lake Bonneville was relatively fresh, it contained small amounts of dissolved salt, including chlorides and sulfates of sodium, potassium, and magnesium. These dissolved salts precipitated on the surface of the Salduro Salt Marsh as the lake evaporated and are the source material from which potash (pronounced potash) is produced.

The Salduro Salt Marsh in particular played an important role in the early development and production of potash or potassium chloride in the United States. The major use of potash is as a fertilizer; lesser amounts are used in the chemical industry. Prior to World War I (1914- 1918), Germany supplied nearly all of the growing demands for agricultural and industrial potash in the U.S. With the blockade of Germany by Great Britain during the war, however, these supplies were cut off, and the U.S. was forced to find alternative sources of potash. By the end of the war, at least 128 U.S. plants were producing potassium compounds from kelp, wood ashes, lake brines, alunite, cement dust, sugar-beet waste, blastfurnace dust, and other sources.

As early as 1906 or 1907, the existence of the salt beds of the Salduro Salt Marsh were brought to national attention by the engineers building the Western Pacific Railroad across the western Utah desert. The salt beds were soon covered by mining claims, and almost immediately the claim owners organized the Montello Salt Company, headquartered in Ogden, Utah. After several years of unprofitable attempts to produce salt, the claims were leased to the Capell Salt Company of Salt Lake City, Utah. Capell erected a small mill near Salduro, about 10 miles east of Wendover, and produced and sold common salt for a short time.

In about 1916, the Capell Salt Company merged into or was transferred to the potash enterprise of the Solvay Process Company (headquarters unknown). During the war years, the Solvay Process Company investigated many saline deposits and in 1916 began to extract potash from the subsurface brines of the Salduro Salt Marsh. The operation was constructed on the south side of the Western Pacific Railroad at Salduro station. There, in the center of the Salduro Marsh salt beds, concentric, circular canals were dug into the salt and underlying muds. Salty water, or brine, flowed into these canals, where it concentrated through the process of solar evaporation. The most concentrated brines were continually pumped inwards, over the dikes separating the outer from the inner concentric canals. Potassium-bearing salts precipitated from the highly concentrated brine within the innermost canal. From there, the salts were harvested and processed to produce potassium chloride.

Production of potassium chloride began in 1917 and, at the end of 1918, Solvay transferred its interest in the potash operation to the Utah-Salduro Potash Company (USPC). By 1920, USPC was the largest single producer of potash in the United States. In 1921, the plant was suddenly closed, due mainly to the reduction of high war-time potash prices and the reorganization of the activities of the Solvay Process Company. After that time, USPC restricted its operations to the production of common salt.

In 1919, the Bonneville Potash Corporation (BPC), formed by J.L. Silsbee of Salt Lake City, erected a potash plant at Wendover, Utah, near the Utah- Nevada border. During the period 1920 to 1936, BPC unsuccessfully attempted to commercially produce potash through the solar evaporation of brines. In 1936, a new operating company, Bonneville Limited, was formed and it built a new plant to recover potassium chloride by flotationrecovery from solar-precipitated salts. The first potash from this new plant was shipped in 1938. By 1939, Bonneville Limited was successfully producing potash and went on to become a significant, long-term potash supplier. Since that time, the operation has survived several ownership changes, and now operates under the name of Reilly Wendover.

A third company, Chloride Products Incorporated (CPI), formed in 1921 by Frank Cook and a group of California capitalists, also attempted to produce potash from the brines of the Salduro Salt Marsh. CPI constructed canals, evaporation ponds, and a small processing plant near Arinosa, a few miles east of the Utah-Salduro operations. CPI’s developmental work is recorded through at least 1925, after which no further information is available concerning their activities.

The growth and development of the potash industry on the Salduro Salt Marsh faced many challenges. The post-war decrease in potash prices made it increasingly difficult for the Utah potash companies to compete with domestic and foreign suppliers. The surface conditions on the marsh were another critical factor. During spring, the surface was normally covered with water, hindering development work, and wave action frequently destroyed dikes and filled the brine-collection ditches with sediment. Also, heavy equipment frequently broke through the salt crust and sank into the underlying mud, necessitating the invention and use of special wide metal wheels on the equipment. Hot, dry summers and cold winters, accentuated by the everpresent wind, made working conditions on the Salduro Salt Marsh unpleasant.

The early production of potash from the brines of the Salduro Salt Marsh by the Solvay Process/Utah-Salduro Potash Company played an important and sometimes singular role in supplying the U.S. with fertilizer during the latter part of World War I. In spite of other U.S. suppliers, international competition, and monumental economical, logistical, and climatological obstacles, the potash industry on the Bonneville Salt Flats has survived. Today, Reilly Wendover, the potash industry’s lone survivor on Utah’s West Desert, is an important contributor to potash production in the United States, and to the economic base of both Tooele County and the State of Utah.