Home/Gauges/Maryland/St. Marys CountySt. Marys County River Gauges4 active river gauges in St. Marys County, Maryland.McIntosh Run near LeonardtownLENM2St. Clement Creek near ClementsCLMM2St. George Creek at Straits Point (IN MLLW)SGSM2St. Marys River at Great MillsGMRM2