Thursday nights at Vertex are Little Black Dress Vodka Ladies Night through May! Vertex Sky Bar, located on the rooftop of the Historic Alex Johnson Hotel in Downtown Rapid City, is open to members and hotel guests. Ladies Night will feature a new cocktail each week for $6, but wear your little black dress and pay only $5! Each week we will have a drawings for great Little Black Dress accessories, and a Grand Prize Drawing of $100 gift certificate for Lillian’s in Downtown Rapid City. Little Black Dress Vodkas offer a variety of flavors including pineapple/honey, black cherry/vanilla and blueberry/pomegranate.