Deseret Chemical Depot The Deseret Chemical Depot ( ) was a U . S . Army chemical weapon storage area located in Utah , 60 miles ( 100 km ) southwest of Salt Lake City . It is related to the Tooele Chemical Agent Disposal Facility . History . The area was used to store chemical weapons between 1942 and 2012 with weapons destruction beginning in August 1996 at the Depot which held , at that time , 45 % of the total U . S . stockpile . After initial demilitarization operations concerning the Weteye bomb concluded a total of 888 of those bombs were left in storage at Rocky Mountain Arsenal . After rounds of protests from residents of Utah , the state ' s governor , and legal action the munitions were transferred to what was then known as Tooele Army Depot South Area . The first transfer of Weteyes took place in August 1981 and the moves continued for three weeks . After these transfers the South Area became known as Deseret Chemical Depot . Disposal operations . , 7 , 593 short ton ( 6 , 888 metric tons ) of chemical weapons have been destroyed using incineration . All GB ( sarin ) was destroyed by March 2002 and all VX by June 2005 . In 2006 , the facility was changed - over to handle destruction of mustard gas in ton - sized containers . By March 15 , 2009 , 3 , 216 ton containers and 54 , 453 projectiles of mustard gas had been destroyed ( 51 . 5 % of Deseret ' s mustard agent stockpile ) . The last explosively configured mustard gas munition was reported destroyed in May 2010 . All Tabun ( GA ) was destroyed by November 10 , 2011 . Disposal of mustard gas containing land mines as well as a small stockpile of Lewisite has not been completed . All disposal operations concluded January 21 , 2012 . Unknown intruder . At 9 : 24 AM UTC - 07 , September 5 , 2002 , officials at the depot triggered the Terrorist Alert Warning System in response to an unidentified intruder being spotted near an old pioneer cemetery , located within the secured perimeter of the depot . The cemetery is roughly a mile north of the incinerator on a hilltop . It was the first time that the alarm , which alerts employees to possible terror threats , had been sounded since new security measures were instituted after 9 / 11 . As soon as the alert was sounded , area schools were notified of a possible terror threat . Due to the proximity of the date of the intrusion to the September 11th attacks the year before , security was even higher than normal , and it was initially reported to KSL - TV in Salt Lake City , Utah that units from the 145th Field Artillery group , a part of the Utah National Guard , had the intruder surrounded . Army officials later stated that the trespasser , who was dressed in dark clothing and fled when sighted by four different soldiers during two different patrols , had escaped the depot . Despite the immediate setting up of roadblocks and a combined search by Army units and helicopters , no trace of the intruder was found . Officials emphasized that the intruder was not in the area where chemical weapons were stored , but " unsettling questions remain " about his intentions , as there was no evidence of anything being stolen or that terrorism was in fact involved .