Hoping to harness the ample power of the Merrimack River, another group of investors began building the Middlesex Canal up the Mystic River, both Mystic Lakes and generally following stream valleys (near to today's MA 38) reached the Merrimack in Chelmsford 35 miles from Boston Harbor, establishing limited operations by 1808, and a system of navigations and canals reaching past Manchester by mid-1814&mdash;and spawning commercial activities, and especially new clothing mills throughout the region.