Observed during a random shoreline search at Bluebriar Park in Granite Shoals (Lake LBJ), 2:50 - 3:30 PM, located in the Colorado River basin in Burnet County, Texas. The lat/long was approximately 30.593, -98.395. We walked approximately 350 feet. The substrate was mostly sand with some silt and gravel. Water levels were down approximately seven feet in Lake LBJ due to an intentional drawdown by the Lower Colorado River Authority (LCRA) for dock maintenance and cleanup after historic flooding in the fall of 2018. The weather was sunny, but cold and windy. 1 shell, 2 valves.