Fallout: New Vegas - Honest Hearts

In Honest Hearts, an expedition into the unspoiled wilderness of Utah's Zion National Park goes horribly wrong when your caravan is ambushed by a tribal raiding band. As you try to find a way back to the Mojave you become embroiled in a war between tribes and a conflict between a New Canaanite missionary and the mysterious Burned Man. The decisions you make will determine the fate of Zion.