STORY HIGHLIGHTSRESIDENTS RECEIVE LETTERS: Residents in Val Verde County, west of Del Rio, received letters from government detailing the possibility of a physical wall WHAT’S AT STAKE: Cave paintings, which date back thousands of years and are considered some of the best in North America, could be damaged WHAT’S NEXT: It’s unclear what the timeline will be for border wall construction, if any wall is built at allThe letterRaymond Skiles Jr., wh…