Every year, on the first Saturday in March, SMRF members volunteer in a massive clean up of the San Marcos River, its tributaries and green spaces. The Texas River Protection Association (TRPA), the City of San Marcos, canoe and diving clubs from all over Texas, as well as civic groups, student organizations and the public participate cleaning up the area from the headwaters to the confluence of the Guadalupe River, a stretch of 90 miles.
