Switchback by Danika Stone

It's a class requirement that they go on an overnight hike in the mountains.  Vale does mind hiking but hates her classmates, except Ash.  Ash gets along with the classmates but has never hiked.  They team together for the mountain hike.  She can help him hike, he can keep the bullies away from her.  It's all going as it should until they stay to pick up some trash left by the bullies and then find themselves alone.  The rest of the kids and the teachers have gone on without them.  They had been counted as being part of the group but left it to make the area pristine again.  Now they are alone and don't know where to go...

Macmillan's Children's Publishing Group and Net Galley allowed me to read this book for review (thank you).  It will be published on May 28th.

They start out on the trail thinking it won't take long to catch up again but they never see the others again.  As they walk along it starts to get dark and begins raining.  Vale knows how to make a shelter and they work on that.  No one brought any matches so they can't start a fire.  Then Vale remembers a technique she read about and uses gum wrappers and a battery to get it started.  

She had to get the fire started because not only was it cold and wet, when she went out to go to the bathroom, she saw deer going through camp and a mountain lion leaped out of their tree to take one down.  She didn't want him coming to visit them during the night.

There's snow in the morning and the trail is buried.  It's getting more dangerous for them by the day.  Especially since now they are in bear territory and it's grizzly bears they have to fear.  They have no food or water so they find water first.

They learn just how far they can go.  Elements can be cruel and so can animals.  Will they finally find help or will they die in the mountains?  It could go either way...