As the number of new coronavirus cases in Montana climbed to 90 on Thursday, Gov. Steve Bullock issued a statewide stay-at-home order to ensure hospitals and intensive care units aren't overrun, and to slow the spread of the virus.

With the number of cases growing quickly and pressure mounting on frontline workers, Bullock said the order was needed to slow the infection rate.

“We have to do more to curtail the spread of this virus,” Bullock said. “In other states, hospitals are overwhelmed and healthcare workers are getting sick themselves. I don't want that to become Montana.”

Thursday's stay-at-home order takes effect at 12:01 a.m. on Saturday, March 28 and runs through Friday, April 10. It requires all businesses and operations in Montana, except those outlined in the directive, to stop all activities in the state.

Under the measure, Montanans are required to stay home outside a few exceptions. They include essential activities, such as getting food or other essential supplies, and to take care of others. They can also go outdoors, so long as they comply with social distancing.

Bullock described the measure as practical under the circumstances.

“This is a direction to stay at home unless you're outside for essential work or essential activities,” he said. “It's asking Montanans to use common sense over the next couple of weeks so we can do everything we can to slow the spread of COVID-19.”

Bullock said certain occupations will also be exempt under the stay-at-home order. That portion of the governor's directive lines up with a March 19 decree from the Department of Homeland Security on “identification of essential critical infrastructure workers.”

Workers exempted from the order include public works, critical manufacturing, verified news media, financial services, chemical workers, energy workers and healthcare workers, among others.

“To determine which businesses and workers are exempt from the orders and should continue working, we're following guidelines largely developed by the federal government,” Bullock said. “This approach will reduce the overall number of infections in our state, and it will preserve our healthcare resources.”

A number of Montana counties reported new cases on Thursday, including Missoula County, which now has seven cases of COVID-19, and Yellowstone County, which now has 14. Gallatin County reported 14 new cases on Thursday alone, bringing its total to 38.

While the virus was reported in just 12 counties on Tuesday, it has since been reported in 15 counties across the state, with 19 new cases coming on Thursday. The first Montana case was reported just 13 days ago.

“It's critical we do everything we can to cut off the chain of transmission and also make sure that we flatten this curve to buy time for our healthcare workers on the front line,” Bullock said. “We know that for every person that stays at home and avoids large crowds, the better our chances to buck this virus and protect our frontline healthcare workers and emergency responders.”

Thursday's stay-at-home order comes two days after Bullock extended an earlier directive to keep schools and some businesses closed for another two weeks, including bars, restaurants and casinos. A number of Montana counties, including Missoula, have taken the directive further, extending it to salons, massage studios and movie theaters.

Bullock called the situation rapidly changing and dynamic and said it wasn't known when Montana could see its cases begin to plateau. The state is also making plans with hospitals in case more care is needed as the virus advances.

“We're doing planning efforts for what happens from a hospital search perspective for local communities,” he said. “We're looking at, to the extent we have to, what other facilities we can use if we have COVID-19 patients that have to be hospitalize and we have to go beyond a hospital's capacity.”