Grace Livingston Hill 
Voice in the Wilderness [PDF ebook] 

Aspiring teacher Margaret Earle heads to the desert to begin her first stint at the head of the classroom. Along the way, she experiences some ups and downs, including a run-in with a menacing cad and some merciless bullying at the hands of a few of her less-welcoming students. But when hero Lance Gardley comes onto the scene, it all becomes worthwhile.