Blood Rush.

Set in 1881 during the American Western Frontier gold rush, the story follows Lucifer’s children, Lilith and Aamon, the original vampires who fly to the Americas to suck the living hope out of the common folk’s blood that’s been revived by the promise of the American Dream, but plans to restore their Vampiric reign are thwarted when an old Familiar shows up, threatening to reveal their true nature if only his complicated feelings for The Vamps don’t bloody the waters.