The National Labor Relations Board rejected an effort by Station Casinos to stop the unionization of workers at Green Valley Ranch.
Those workers voted in November to join Culinary Local 226 and Bartenders Local 165.
Green Valley Ranch is the fourth Station Casinos-operated property to unionize since 2015.
The Las Vegas Review-Journal reports that Station Casinos is also challenging the April vote to unionize by workers at the Palms.
