April 11 marks National Ranch Water Day, and while it may be among the newer drinking “holidays,” it’s easy to see why folks clamor for the Texas-born sipper. The homegrown cocktail has taken the nation by storm, thanks to its simple prep — it uses only tequila, fresh lime juice and sparkling mineral water — and no-fuss, low-calorie thirst quenching. These San Antonio hotspots are offering specialty Ranch Water cocktails on the big day.