More than a dozen volunteers underwent training on a recent Sunday to become certified water quality monitors. Above, Rachel Sanborn, volunteer coordinator for the San Marcos River Rangers, hurls a bucket over the river to demonstrate getting a good sample for testing. Daily Record photos by Denise Cathey
River Rangers riding herd on the San Marcos
When a cold snap killed an unknown number of invasive catfish last month, Rachel Sanborn was among the first to know.