According to studies by FEMA and the Utah Geological Survey, it's not a matter of if it happens but when.
The drill begins at 10:15 a.m. on Tuesday, with a hypothetical 7.0 magnitude earthquake.
"We found that people have just really taken this and run with it," said Joe Doughtery, Division of Emergency Management. He said 900,000 Utahns, over 30% of the state's population, have signed up to participate in the drill.
FEMA identified Utah as a priority for a disaster two years ago and say the Wasatch Front is overdue for an earthquake of that magnitude.
The Salt Lake Valley Health Department Offices and Public Health Clinics will be closed Tuesday, so its employees can put their emergency response training to the test.
Events are planned for all over Utah. To find out more about the drill, visit The Great Utah ShakeOut.