Peering into the freshwater springs of San Marcos through a glass-bottom boat is a little like peering back into Texas history. Groundwater bubbles and gushes through ancient limestone to refill the clear, dark turquoise waters of Spring Lake. On the lakebed you can still faintly see the once-tumultuous geologic fault line, where the Hill Country meets the Blackland Prairie, that created these springs millions of years ago.
Archeologists think this area is one of the oldest continuously inhabited places in North
