Neon Moon by Grace R. Reynolds

Darlene Boone is a survivor. For more than a year, she's been bartending at the famous Teegarden Saloon, a honky tonk in the Texas Hill Country, while attempting to put her life back together in the wake of an abusive past. But when an axe-wielding maniac descends on The Teegarden during one of the bar's busiest nights of the year, Darlene, along with everyone else in the crowded establishment, will have to put down their whiskeys and take up the nearest weapon if they're to survive this unexpected night from hell. No one knows if they'll make it out alive, least of all Darlene, but one thing's for sure no matter what: Texans don't go down without a fight.