Constructed between 1835 and 1839 of limestone extracted upstream on Tonoloway Creek, Tonoloway Aqueduct carried canal boats across Tonoloway Creek, a 31-mile tributary of the Potomac River. Cement for the aqueduct came from Captain Hook’s mill but during a water shortage in the summer of 1837, cement was imported from Boteler’s Mill and Baltimore. Having trouble pronouncing Tonoloway? In the 1700s, surveyors often recorded the creek’s name as “Conoloway.”