If you happen to see smoke billowing above Glacier Park International Airport and some 50 bodies strewn across its grounds Saturday, be not afraid.

Local emergency responders, the airport, Kalispell Regional Medical Center and North Valley Hospital will hold a mass casualty exercise between 9 a.m. and 1 p.m. Saturday to test regional disaster plans.

The full-scale exercise will simulate the aftermath of a jet crash from just after impact to subsequent medical treatment at the two hospitals.

Emergency medical service workers and volunteers will assess their ability to respond to such an event, communicate among themselves and transport large numbers of victims to medical facilities.

Cindy Mullaney, Flathead Office of Emergency Services deputy director, said the goal of the exercise is to test the county’s new mass casualty and mass fatality plans.

She said the event will represent the most comprehensive assessment of area emergency response in recent memory.

“Basically it’s just to make sure the plans we have written are where we need them to be,” Mullaney said. “You can sit in a room and talk about it and it all sounds very good, but when you put it into practice it doesn’t always go like you planned.”

The idea is to expose existing or possible holes in communication, transportation and cooperation between agencies. Some gaps have already been exposed, she said, adding that she hopes additional shortcomings are brought to the surface Saturday.

“If everything goes right in this exercise, something is wrong,” Mullaney said.

Electronic reader boards will be placed along nearby roadways to inform motorists that an actual emergency is not under way.

Mullaney said those passing through the area can expect to see large numbers of emergency responders beginning at about 9 a.m.

Fake injuries will be assigned to some 50 volunteers who will begin the exercise lying on the ground as medical personnel descend on the area. From there, they will be transported to Kalispell Regional and North Valley Hospital where staff will assess their own mass casualty response.

Among those participating in the exercise will be the county Office of Emergency Services, Montana Highway Patrol, Flathead County Sheriff’s Office, Kalispell Police Department, Flathead 911 Emergency Communications Center, Evergreen Fire and Rescue, Glacier Park International Airport, Three Rivers EMS, Creston Fire Department, Bigfork Fire and Ambulance, Whitefish Fire Department, Whitefish Police Department, Columbia Falls Fire Department, Columbia Falls Police Department, Olney Fire Department, West Valley Fire Department, Somers Fire Department, U.S. Border Patrol and Lakeside Quick Response Unit.