Bonneville Salt Flats Timeline

The following is a historical snapshot of Utah’s Bonneville Salt Flats since 1846. It references actions relating to motorsports, mining, scientific and engineering studies, federal land management and legislation. The timeline was compiled by the Save the Salt Foundation, a nonprofit organization whose mission is to protect the land and promote its history and motorsports legacy.


Ill-fated Donner-Reed party crosses the Bonneville Salt Flats (BSF) on the way to California. Wagon tracks can still be seen on the edges of the BSF.


G. K. Gilbert publishes “Lake Bonneville: U.S. Geological Survey” (May 1, 1890).


Bill Rishel becomes first man to cross the salt flats on a bicycle in a 3,000-mile coast-to-coast race. A.L. Westward of the National Trails Association, declares BSF “the greatest speedway on earth.”


Western Pacific Railroad line constructed through BSF. The railroad pierced the center of the Salduro Marsh towards Wendover. Records and studies of work performed cite numerous difficulties encountered in constructing the railroad due to the salt flats thickness and hardness.


Salt mining (but not potash mining) begins in the area with a team of horses and a single plow blade. The town of Salduro was at the center of the thickest section of the salt crust.


Future Salt Lake City Mayor, Ab Jenkins became the first person to ride a motorized vehicle across the salt flats on his motorcycle.


Everett Carpenter publishes Ground Water in Box Elder and Tooele Counties, Utah.


First unofficial land speed record set at the BSF by Teddy Tetzlaff. He remarked on the smoothness of the salt and how the coolness of the salt surface did not overheat tires. Top tire companies began testing tires on the BSF by sponsoring events. Utah Governor William Spry watched Tetzlaff race and rode with him in the record-setting car. Tetzlaff was racing on an area south of the railroad tracks now currently being mined.

Chicago: “The Railway Age Gazette” pronounces “this natural racing-track is a level bed of salt, 98% pure…The salt-beds are 65 miles long and 8 miles wide. The estimated depth, in the middle, is 12 – 15 feet.”


First recorded destruction of BSF. Salt Lake Tribune, Sept. 12, 1915 article: “Mighty Bed Of Salt Being Scooped Up For Use Of Mankind.” Opening paragraph states, “The world’s greatest natural speedway is being torn up and ground up and dispensed to the public in cartons and packages…,The largest deposit of pure salt yet discovered is being marred, is disappearing…,The saline deposit covers a surface area approximately sixty-five miles long and twenty-five miles wide.”


Doc: Anonymous, Potash in the lake muds of western Utah: U.S. Geol. Survey Press Bulletin 271, May, 1916. Gale, H.S., Potash in Salduro salt deposits: Eng. and Min. Jour., vol. 102 pp. 780-82 , Oct. 23, 1916.


Utah-Salduro Company (subsidiary of Solvay Process Co.) begins harvesting minerals from the BSF for potash production.

Doc: Gale, H.S., Potash in 1916: U.S. Geol. Survey Mineral Resources, 1916, pt 2, pp. 98–100, 1917.


Brine collection ditch dug at Salduro Loop (facing the mining area). The spoil from the ditches were piled up to construct the dike around the Salduro Loop (facing the racing area). These ditches would later be abandoned, leaving mud tailings from the dike within just feet of the historical speed and endurance racetrack that would, through wind and water erosion, begin to infiltrate salt crust.


Victory Highway (Highway 40) constructed through BSF. Future mayor of Salt Lake City, Ab Jenkins, raced a train from Salt Lake City to Wendover and won as part of celebration.


Congress gives 40 sq. miles to The Bonneville Corporation. Combined with the 49 sq. miles acquired from the Utah-Salduro Co., the mining company now has a total 57,500 acres.


Study: Thomas B. Nolan, Potash Brines in the Great Salt Lake Desert, Utah, U.S. Geological Survey Bulletin 795-B. “The salt is reported to reach a maximum thickness of 5 feet near the central portion of the deposit. The greatest amount found during boring, however, was 3½ feet near Salduro station. From the maximum it thins rather gradually to zero at the edge.”

1933 – 1957

Ab Jenkins begins his triple decade career of setting 56 AAA Contest Board National Speed and Endurance Records on BSF. Hundreds of records would follow.


First internationally recognized World Land Speed Record set by Britain’s Sir Malcolm Campbell; new record prompts international land speed racing community to relocate all future efforts from Daytona Beach, Florida to the BSF. Ab Jenkins was directly responsible for epic shift.

Britain’s John Cobb sets 24-hour endurance and 21 additional world speed records inside a week on the BSF. Jenkins, now Salt Lake City mayor, sets a land speed record on an Allis-Chalmers tractor.


Bonneville Ltd. acquires potash mining operation.

Ab Jenkins, SLC mayor, driving his “Mormon Meteor” designed by Augie Duesenberg, sets 72 records, some of which would stand for nearly 50 years.


Bureau of Land Management (BLM) becomes custodian of the BSF.


Britain’s John Cobb runs his 400 mph race car on BSF as part of Utah’s Centennial. The official program declares “The salt is like concrete. Bonneville is the world’s finest race course for several reasons. Its extreme hardness gives speeding cars maximum traction…”


First “Bonneville National Speed Trials” (precursor to modern “Speed Week”) held at the BSF.


General Motors names its all–new 1957 Pontiac model “Bonneville” after Ab and Marvin Jenkins set every American records possible with new car.


Federal government issues potassium leases covering 24,699.83 acres on the BSF to Bonneville Ltd.; leases cover area north of the highway and just east of the BSF race tracks; collection ditches dug on leases to allow for withdrawal of salt brine for potash production. The 14 miles of collection ditches were open to surface water from the raceway.


Kaiser Aluminum and Chemical Corp. acquires potash mining operation.


Kaiser requests permission from U.S. Geological Survey (USGS) to begin pumping from the collection ditches north of Hwy 40 into the potash mining operation.


Mining company abandons Salduro Loop ditch.

Early 1960s-1970s

Racers began noticing a problem with the salt crust.

Late 1960s-1970s

Studies undertaken Utah Geological and Mineralogical Survey and the U.S. Geological Survey to determine extent of salt loss at the BSF.

1963 – 1970

Craig Breedlove driving “Spirit of America,” Art Arfons, Driving “Green Monster” and Gary Gabelich driving “The Blue Flame” focus worldwide attention on BSF driving handbuilt jet and rocket-powered cars that reclaiming World Land Speed Record from the British. From 407 mph, the Americans raised the bar to 622 mph.


Last World Land Speed Record set at BSF by Gary Gabelich; salt loss forces international land speed racing community to move record-setting venue to Black Rock Desert and other locations due to reduced length of BSF race track.


Interstate 80 constructed across the BSF replacing Hwy 40.


Hydrogeology of BSF studied by Utah Geological and Mineral Survey; study notes that brine under the salt flats is “collected by a system of ditches and transferred to solar evaporation ponds where potassium chloride salts are precipitated and harvested…” and that “shallow brine aquifer is the uppermost 25 feet of lacustrine sediments. Because the brine is harvested for its potash content, it has been explored in more detail than the rest of the hydrologic system.”


Utah Geological and Mineral Survey conducts study comparing salt crust thickness in July 1960 to October 1974 and determines there was a 100% decrease in cubic yards of salt crust over 4 feet thick during that time period.


Bonneville Salt Flats Race Track added to National Register of Historic Places


State of Utah turns over maintenance of the flats to the BLM in 1976. BLM abruptly decides that one race event a year (Speedweek) does not constitute enough public interest to continue decades-long racetrack surface preparation.

To counter the BLM’s ultimatum that racers needed to: “use it or lose it,” land speed racing community respond by forming a second sanctioning body - Utah Salt Flats Racing Association (USFRA) – to host additional racing events. Long-time permit holder Southern California Timing Association/ Bonneville Nationals, Inc. (SCTA/BNI) later added an October event: World Finals bringing the annual racing to four events per season.

The USFRA, comprised mainly of Utah residents, provides local stewardship and an effective BLM watch group.


U.S. Geological Survey and BLM study “Hydrology and Surface Morphology of the Bonneville Salt Flats and Pilot Valley Playa, Utah”; study concludes: “Weather cycles may partly explain changes on the Bonneville salt crust. But the activities of man, such as withdrawing brine and constructing surface-drainage barriers, have altered the hydrologic environment and have had a profound effect on the salt crust. Water-level data indicate that during 1976 brine was moving through the shallow-brine aquifer on the Salt Flats from the area of salt crust toward all areas of manmade discharge (brine-collection ditches east and south of the salt crust and alluvial-fan wells west of the salt crust).” Study also says: “Elimination of brine withdrawals from the ditch system north of the interstate highway would eliminate a yearly loss of about 680 acre-feet of brine and 270,000 tons of salt.”


Britain’s Richard Noble abandons BSF for Nevada’s Black Rock Desert due to reduced length of the international speedway. This removes BSF as the absolute world record-setting site. Noble sets 633 mph record on Black Rock.


30,203 acres of the BSF designated as Area of Critical Environmental Concern and identified as the Bonneville Salt Flats Special Recreation Management Area.


Rick Vesco photographs massive amounts of mud sloughing off the mining tailings next to the raceway installed by the mining operations. He also noted water being drawn off the surface of the salt flats into the NE collection ponds 17 miles in length.


Reilly Industries, Inc. acquires potash mining operation.


Save the Salt Coalition is founded by racers, businesses and community members with common goal of saving the BSF.

BLM Recreational Lands Manager, Gregg Morgan interviewed by ESPN notes, “We are concerned with the loss of salt on the perimeter and with the overall loss. The study we completed a year ago, which updates the one we did 14 years ago shows that we are losing 1% of salt from the surface each year. That amounts to 1.6 million tons annually. At that rate, in ten years possibly there will not be enough salt to race on and in thirty years not enough salt to sustain what we call the Bonneville Salt Flats.”

Save the Salt Coalition (STS) is founded by racers, businesses and community members. Their mission is to protect the Bonneville Salt Flats in Utah and to promote its history and motorsports legacy. The group aspires to keep this national treasure available for future generations.


After years of warning the BLM that conditions at the BSF are deteriorating, the racing community is apoplectic about poor conditions and continued salt loss; racers approach Congress in an attempt to force the BLM to take action.


S. 1184 introduced on May 24, 1991 by Sen. Jake Garn (R-UT) and Sen. Orrin Hatch (R-UT) to require Sec. of Interior to conduct a study to determine the nature and extent of the salt loss from the salt flat crust occurring at Bonneville Salt Flats, Utah and authorizes appropriations for same; H.R. 1727 introduced on April 11, 1991 by Rep. James Hansen (R-UT) to require Sec. of Interior to conduct a study to determine the nature and extent of the salt loss from the salt flat crust occurring at Bonneville Salt Flats, Utah; H.R. 1096 amended on July 23, 1991 by Rep. Wayne Owens (D-UT) to require Sec. of Interior to conduct a study to determine the nature and extent of the salt loss from the salt flat crust occurring at Bonneville Salt Flats, Utah.


The speedway lengths have shrunk to such a degree that it forces Bonneville Nationals and Speed Week officials to change international timing procedures. No longer could they support the required two-way runs within an hour and concentrated on only setting national records.

Save the Salt Foundation (nonprofit organization) established to help raise funds to save the BSF. The Foundation shares the same mission with the STS Coalition, to protect the BSB and to promote its history and motorsports legacy.

Public Land Order 6941 withdraws 30,203 acres of the BSF from surface entry and mining for period of 20 years, but does not impact the federal mineral leases.


H.R. 1603 introduced on April 1, 1993 by Rep. Bruce Vento (D-MN) to authorize appropriations for BLM for fiscal years 1994-97 and require Sec. of Interior to conduct a study to determine the nature and extent of the salt loss from the salt flat crust occurring at the BSF.


Racing community, mine owner Reilly, the BLM and the state of Utah negotiate a voluntary agreement to restore the BSF whereby Reilly will pump salt brine back onto the BSF during the winter months for five years beginning in 1997.


Reilly begins pumping salt brine onto the BSF under voluntary salt laydown project. Independent testing of salt brine and surface samples reveal consistency is excellent for supporting racing vehicles.

U.S. Geological Survey entitled “Investigation of Salt Loss from the Bonneville Salt Flats, Northwestern Utah” explains that “[m]aximum salt-crust thickness was 7 feet in 1960 and 5.5 feet in 1988.” Study concluded that “[w]ith an estimated net loss of salt from the shallow-brine aquifer, the dissolved-solids concentration must be maintained by dissolution of the salt crust.”


Voluntary pumping agreement expires but Reilly chooses to continue pumping operation.


BLM Professional Geologist W.W. White III evaluates success of the voluntary pumping program: “The 2-inch increase to salt-crust thickness expected as a result of the project was not observed in measurements from recent test pits and auger holes excavated in BSF….excepting contribution to the new salt-crust area, most of the 6.2 million tons of salt transported to BSF was apparently incorporated into the underlying shallow-brine aquifer.”

White also notes: “The capability of the shallow-brine aquifer to accept additional NaCl is significant, because it is the shallow-brine aquifer that regulates the distribution of NaCl mass to the BSF salt crust. If the Laydown NaCl mass is assimilated by the shallow-brine aquifer, then: 1) one would anticipate an increase of NaCl concentration in the affected area of the shallow-brine aquifer, and 2) it would not be unreasonable to expect that more halite mass would be added to the existing salt crust as a result of this increased NaCl concentration.”

Intrepid Potash, Inc. acquires potash mining operation from Reilly; BLM and the Utah Division of Oil, Gas and Mining request Intrepid submit a new mining plan.


Intrepid submits draft mining plan; BLM denies racing community the opportunity to participate in reviewing/commenting on the mining plan.


Intrepid and BLM prepare an Environmental Assessment (EA) on the mining plan; racing community provides extensive comments on the plan including the fact that under preservation law, the BSF Historic Registry listing triggered obligations by the BLM to consult the State Historic Preservation Officer (SHPO), provide an opportunity for the Advisory Council on Historic Preservation to comment, and provide the racing community with “interested party” status.


BLM approves mining plan and final EA contingent on Intrepid continuing the salt laydown project and returning an amount of salt in brine form equal to the amount of salt they remove from the BSF; the BLM explains that it has not informed the SHPO of degradation at the BSF “[b]ecause it has never been determined that the conditions of the BSF are attributed to the mining operations, the BLM did not believe it needed to inform the SHPO of anything”; strangely, the BLM also opined in the final EA that “[r]emoving mineral from the shallow brine aquifer north of I-80 may be causing the salt layer to thin and retract. Intrepid’s voluntary continuation of the salt laydown project may not be sufficient to prevent diminishment of the Bonneville Salt Flats (BSF) from drawing off the brine from adjacent areas. Such diminishment would degrade the unique geology and historical relevance of the site and would disrupt the recreational opportunities that have been part of the BSF for over 80 years.”

BLM denies Save the Salt’s request for “interested party” status and encourages “the Coalition to seek salt laydown results directly from the [mining] Company.”

Public Land Order 6941 extended and set to expire on August 5, 2032.


Racers continue to see degradation at the salt flats and worsening conditions on and around the race courses; the racing community, acting through their nonprofit “Save the Salt,” request BLM allow a dry salt laydown test to determine whether dry salt laydown is viable; numerous exchanges between Save the Salt representatives and the BLM take place in which BLM requests further details.


After months of exchanges, BLM indicates that the test may interfere with their own ongoing studies and requests Save the Salt prepare an abbreviated EA.

Save the Salt works with Bingham Engineering to help prepare the abbreviated EA; based on the engineering report, Save the Salt determines it will not be able to afford the EA process and dry salt laydown plan.

An estimated 2,000 tons of salt were successfully deposited on the mud surface at the end of the access road to the BSF racing area; the surface had originally been covered by salt but has been reduced to mud due to continued salt loss over the years.


Save the Salt Coalition develops alternatives for improving the conditions at the BSF. The document is called a “draft reclamation plan” and is shared with the BLM, Intrepid, members of Congress and state officials and the racing community. The Coalition, BLM and Intrepid begin discussions on ways in which to protect and restore the BSF.