According to the local news report, 3 things that tend to go together into a bundle that seems to repeat itself a lot out there:
1. North Idaho
2. Inattentive
3. Pickup truck/SUV

There are 2 distinct possibilities that fit a pattern in the area:
1. Beater truck in less than perfect mechanical condition driven by somebody distracted by either the aforementioned operational issues, reaching for the Camel pack, amunition box fell onto the floor, radio too loud, or dog did something stupid.

or

2. Recently transplanted California resident on cell phone or changing the DVD in the player to keep the kids entertained while transporting them to some event.