Vampires of El Norte: Isabel Canas

Vampires and vaqueros face off on the Texas-Mexico border in this supernatural western from the author of The Hacienda.

Nena knows a thing or two about monsters—as the daughter of a rancher in Mexico, her home has long been threatened by tensions with Anglo settlers from the north. But something more sinister lurks near the ranch at night, something that drains men of their blood and leaves them for dead--something that once attacked Nena nine years ago.
Believing Nena dead, Nestor has been on the run from his grief ever since. He has night terrors of sharp teeth, and is haunted by the life he and Nena could have had together.
When the United States attacks Mexico, the two are thrown together on the road to war. But the shock of their reunion—and Nena’s rage at Nestor for seemingly abandoning her long ago—is quickly overshadowed by the appearance of a nightmare made flesh.
Unless Nena and Nestor work through their past and face the future together, neither will survive to see the dawn.