The San Marcos - A River Story details the rich history of a central Texas river named the San Marcos River. The San Marcos springs have flowed for around ten million years. In The San Marcos - A River Story, author Jim Kimmel brings us a picture of a watercourse brimming with life, past and present. Native, non-native, prehistoric, and modern-day plants, animals, and people have inhabited the river and its banks for years, and Kimmel touches on them all with the affectionate and knowledgeable voice of one whose own life has been closely linked to the San Marcos.