The Coonamessett River, (Latitude: N4l°34.913', Longitude: W 070° 34.412') is a largely groundwater fed coastal river in Falmouth, Massachusetts on Cape Cod. Location It is one of Cape Cod’s largest rivers, flowing approximately 3 miles from the 158- acre kettlehole Coonamessett Pond to the Great Pond estuary and thence 2 miles to Vineyard Sound. Fish The Coonamessett River once contained some of the largest populations of five species of diadromous fish in southeast Massachusetts – Alewife, Blueback Herring, American Eel, White Perch, and sea-run Brook Trout. History Pre-colonization Humans have modified the river for centuries with mill construction and cranberry cultivation along the banks and its alluvial valley. The Coonamessett River was important to the native people of Cape Cod and to the immigrants who settled here. Coonamessett means “long fish, white pine place” in Wampanoag, also known as the Wôpanâak language. The “long fish” likely referred to Atlantic eels that can still be found in the river Long ago nearly the entire river may have been bordered by red maple or white cedar swamp when the Wampanoag fished for herring. European settlement After European settlers arrived in 1660, the river was initially known as the Five Mile River. Philip Dexter located Falmouth's first grist mill at its mouth around 1700, and by 1795 there were three mills along the river with a corresponding decline in fisheries. Herring war and bylaws A "herring war" began in 1798 with a bylaw giving an elected committee the right to remove any obstructions to allow fish free passage from April 1 to June 10. Tensions reached a peak in 1805 when the anti-herring group packed a cannon on the Village Green with herring. It exploded, killing the gunner. In 1865 further vestiges of the war appeared with another bylaw that read: Voted that the herring of rivers of the town be allowed to pass up and down said rivers into the ponds unmolested, from 12 o’clock, noon Saturday, to 12 noon on Monday each week, except that the herring in Coonamessett River be allowed from 10 o’clock at night to 5 in the morning of each day in the week unmolested in addition. Conversion of wetland In 1891 the Swift brothers converted river wetlands into cranberry bogs, thus straightening, diking, damming, and channeling the river, reducing some sections to a simple ditch, although much of the river today remains a meandering stream wending