The Texas Water Safari event has run every year since 1963; it uses canoes powered only by human muscle.

The Texas Water Safari is billed as the "World's Toughest Boat Race" and runs annually on the second Saturday of June.

The clean-up is coordinated yearly by Tom Goynes, president of the Texas River Protection Association, and is usually the first Saturday of every March.

The fountain darter is characterized by the mottled brown body and dark markings that help it camouflage into the bottom of the San Marcos River banks.

An endangered plant species specific to the San Marcos River is Texas wild rice.

[6] The San Marcos River is considered to be one of the most biologically diverse aquatic ecosystems known in the Southwestern United States.

Critical habitat refers to a particular geographical area that contains all of the physical, chemical and biological attributes needed for the continued success of an endangered plant or animal and that may require special efforts for their management and protection.

[8] Work on the San Marcos River banks are the main focus of the restoration projects in a large effort to protect the Edward Aquifer.

The city was to spend close to $1 million in this restoration attempt, to makes the river a more ideal habitat, while at the same time improving recreation.