From “History of Chelmsford” by Wilson Waters and Henry Spaulding Perham (Courier Citizen, 1917):
“… Down as late as 1820, there were caught, mostly at this spot [site of the large mill of the Middlesex Company], and at the foot of Pawtucket falls, twenty-five hundred barrels of salmon, shad, and alewives, besides many other fish of less value.
“The mill operatives in the early days protested to the boarding house keepers that they could not endure to eat salmon more than three days a week.
“Gilman says: ‘Before the progress of the waters of the Merrimack to the sea had been checked and restrained by dams they bore in their bosom a bountiful source of supply for the sustenance of not only the Indian, but also the first English settlers. Within the memory of the oldest inhabitant now living (1880), the Merrimack teemed with salmon, shad, alewives, and eels. Occasionally a sturgeon was seen leaping, in sportive activity, high in the air.” This is what one of the oldest inhabitants now living (Captain Silas Tyler) says: ‘The best haul of fish I ever knew was eleven hundred shad and eight or ten thousand alewives. This was in the Concord River, just below the Middlesex mills. Formerly, there was what was called an island fon the Belvidere side of the bridge, near the mouth of the Concord. Occasionally, the water from the Concord River found a course down by the Owen house and the old yellow Tavern house. There were four fishing places, two above and two below the Concord River bridge. Joe Tyler, my uncle, owned those above, and Josiah Fletcher, those below the bridge. … The law allowed us to fish two days each week in the Concord, and three in the Merrimack. … People would come 15 or 20 miles on fishing days to procure these fish. Shad were worth five dollars per hundred, salmon ten cents per pound.”