Readers ask: “Where exactly is the Balcones Fault?” And while we’re at it, “What precisely is the Balcones Escarpment?” The easiest answer: The fault and the escarpment, named for the Spanish word for “balconies,” signal the start of the Texas Hill Country. Or, in some places, they mark the transitional zone between the rugged hills to the west and the gently rolling plains and Blackland...