- San Marcos River -
The San Marcos River begins at Aquarena Springs in San Marcos and is joined by the Blanco River about 4 miles downriver and flows southeast for 75 miles, forming the boundary between Guadalupe and Caldwell counties and part of the boundary between Gonzales and Caldwell counties, before reaching its mouth on the Guadalupe River, two miles west of Gonzales. Activities include swimming, snorkeling, scuba diving, tubing canoeing and kayaking. Enjoy the clear waters if the San Marcos River and make sure to stay over night at one of the many campgrounds along the river.
