A Mill River History Parts 1 & 2: Introduction and Geological History

Visualization of Northampton and Amherst Under Lake Hitchcock. UMass, NE Friends of Pleistocene Conf. 2000

Visualization of Northampton and Amherst Under Lake Hitchcock. UMass, NE Friends of Pleistocene Conf. 2000

A Mill River History: Parts 1 & 2

John Sinton © Novembeer 2014

Rivers aren’t constrained by human desires and stories; they sing the beauty of their own randomness and drift.”   — Jeremy Denk[i]

1. Introduction

       Start with an incline, which has no intent; add rain, whose only option is to fall, and time, which can do nothing but pass. This is how rivers begin.

     — Barbara Hurd

a. The Course of the Mill River

Tumbling out of its headwaters at Upper Highland Lake in Goshen at 1,440  feet above sea level, the river’s West Branch drops 910 feet in six miles to Williamsburg at 530 feet, where it meets the West Branch flowing, also for six miles, out of Conway State Forest, then down another 105 feet in 1.9 miles to Haydenville at an elevation of 425 feet.  Picking up tributaries from Beaver Brook and Roberts Meadow Brook, it drops 95 feet in 2.4 miles to Leeds at 330 feet, then another 100 foot drop in 2.3 miles to Florence at 230 feet, down to Paradise Pond at 130 feet in 2.3 miles, slowly dropping a final 20 feet in 1 mile to the meadows of the Connecticut River at 110 feet above sea level.  That is a total drop of 1,330 feet from Goshen to Northampton.  The river distance from Williamsburg to Northampton is about 10 miles and from Goshen to Williamsburg about 6 miles.

Along the first steep drop of almost 1,000 feet from the hilltowns of Goshen, Ashfield and Conway to Williamsburg, the Mill River carves a steep valley, eroding and depositing rocks and boulders, creating the small waterfalls where European settlers later placed dams – Williamsburg, Haydenville, Leeds, Florence, and Paradise Pond.  However the nature of the Mill River changes dramatically after it leaves the steep slopes of Goshen, Conway, and Williamsburg.  The topography flattens out, and from Leeds downstream, the Mill meanders between glacial deposits at Baker Hill, Yankee Hill, and Fort Hill on its way into Hulburt’s Pond (the ancient Oxbow at Mass Audubon’s Arcadia Refuge).

b. The Signal Purpose of the Mill River

The Mill River has a simple purpose to fulfill – to move water and sediment.  It picks up water from precipitation and underground springs and erodes rock and fine sediment from its valley, all of which it deposits downstream.  The physics of the transport of its water and materials is also pretty simple – the more water the river carries and the steeper the gradient down which it flows, the faster the current and the more power it has to carry material downstream.  In dry periods and on flat land, it erodes less and deposits more, while in wet periods and in steep terrain, the opposite applies.  During catastrophic weather events the river’s power becomes fierce, as it carries millions of tons of materials downstream, including trees and houses.  Wherever the river finds a way to spread its water, the force becomes spent and whatever it carries is deposited on the flatland.

c. The River Gives Life

 An array of plants and creatures find that different parts of the Mill Valley suit their own purposes.  The upper reaches of the stream, draining beaver swamps, support a population of algae, a fewflowering plants, some small brook trout and minnows, several species of aquatic insects (mayflies, stoneflies, and blackflies among them), and frogs, clams, crawfish, and worms – the sorts of creatures that children love to play with.  Because the Mill runs through rocks with few nutrients that would nourish microscopic life on which insects feed, it supports a comparatively modest biota.  The upper part of the watershed, however, supplies people with the drinking and bath water they need.  Think of it this way: The cleaner the water, the less life it supports, the dirtier it is, the richer the biota.

As the water of the Mill River reaches the flatter sections of Williamsburg, it deposits its Hilltown sediments in periods of low water and carries them farther downstream in high water.  Furthermore, aquatic plants find anchorage in the slower waters, and those plants provide food and hiding places for more insects and minnows, so the fish population begins to increase.  Since the water is still cold, even in summer, trout remain the most common fish.  The number of birds also increases, as the burgeoning insect, plant, invertebrate, and fish populations provide food for kingfishers and herons, flycatchers and waxwings, mergansers and mallards.

 As the river winds down through its steep-sided valley from Williamsburg through Haydenville, Leeds, and Florence to Paradise Pond, it provides habitat for mink, otter, muskrat, and beaver.  While the water remains cold much of the year, it warms considerably during the low flows of the summer months when plenty of insects, minnows, and crawfish can be found.  Meanwhile, trout find refuge in the deeper pools or near springs where they can escape the heat.  It is only below Paradise Pond where warm water fish show up in good numbers, chiefly bass, pickerel, and perch.  By the time the Mill enters Hulburt’s Pond, it shelters more species of invertebrates and fish, such as carp that can be found in the Oxbow and the main stem of the Connecticut.

It is doubtful that the Mill ever hosted many migratory fish – shad, salmon, eel, and lamprey – which in springtime swim up and then, in autumn, back down the Connecticut.  Migratory fish look for strong currents to swim against as they move upstream, and the mouth of the Mill probably never entered the big river at a point where currents are strong, but joined the big river in areas of slack water where there are floodplain forests of silver and red maple, sycamore, and cottonwood.

2. The First 20,000 Years[ii]

Twenty thousand years ago, glaciers covered the Pioneer Valley, and there was no Mill River to be seen because it lay underneath the ice.  The bed of the Mill River had already been cut in previous interglacial periods during the more than two and a half million years of the Pleistocene epoch.  After the last of the glaciers retreated in our region about 20,000 years ago, the Mill River was once again revealed, and over the course of the next 6,000 years, it helped shape the landscape through which the river now runs.

The most significant post-glacial feature in the Connecticut River Valley was a 250-mile-long series of interconnected post-glacial lakes called Lake Hitchcock, named after the 19th-century Amherst College geologist, Edward Hitchcock.  Stretching from Rocky Hill, Connecticut to Burke, Vermont, Lake Hitchcock began draining from south to north sometime between 14,000 and 15,000 years ago when the dam of glacial debris at Rocky Hill, Connecticut gave way under the growing rush of melt water.[iii]

The glaciers melted in a stop and go fashion, leaving behind a series of smaller lakes, the last of which was called Lake Hadley in the Northampton-Hadley area.  A post-glacial lake remained in the Northampton region for about 1 to 1.5 thousand years, and, as it began to retreat from Northampton some 14,000 years ago, it left behind the sediments from its lake bottom composed of fine-grained silt, sand, and clay that lie underneath much of Northampton from the meadows along the Connecticut River to Florence.

At its highest, the surface of Lake Hitchcock in Northampton was about 300 feet above current sea level, which means it covered the whole of Northampton from the Florence meadows to the Connecticut River.  Some of the silts and clays from the lake bottom have been covered up in Northampton by the outwash of post-glacial materials that were swept down from the hilltown areas, and some have been covered by the sediments that the Connecticut River deposits over the meadows during flood periods.

A lot happens underneath a glacier – its billions of tons of ice move small mountains, erode hillsides, deposit huge boulders and enormous mounds of ground-up soil.  Glaciers don’t suddenly melt, but disappear in periodic episodes of melting and refreezing that lead to the accumulation of water in periglacial lakes – lakes that are associated with the freezing and thawing of water and ice.  This allows for the formation of lake deltas and river terraces, as well as the accumulation of large piles of sediment, which are deposited as uniquely shaped hills that geologists call drumlins.  Meeting House Hill (Main Street in Northampton), Baker Hill, Round Hill, Hospital Hill, and Fort Hill are all drumlins or deltas.  Meanwhile, farther upstream, the Mill River re-occupied its pre-glacial valley, eroding away glacial sediments – the rocks, boulders, and gravels that the Mill currently deposits downstream of Williamsburg.  If you dig or drill beneath the streets of Northampton, you will discover the sediments of the old lake bed.           

This is the geological trail you will travel from the Mill River’s headwaters to its mouth: From the hilltowns of Goshen, Ashfield, and Conway down to Leeds, the Mill holds to the riverbed it created before the last glaciation, down a steep valley, eroding bedrock and glacial sediments downstream toward Northampton.  After the falls at Leeds, it spreads out onto the Florence meadows, which is the highest point covered by Lake Hitchcock.  From Florence downstream, the Mill has entrenched itself in meanders, which it has carved into delta sediments around mounds of boulders, rocks, pebbles, and sands that the last glacier deposited.  In some spots, such as the mill dams at Florence and Paradise Pond, it continues to erode harder rock outcrops at the dam sites.  Mill owners built dams at these small waterfalls to control river flows for their waterwheels.

This is what you will see in cross section if you drill down through the sediments at Smith College: On the surface are sandy soils that the post-glacial Mill River deposited in the center of Northampton.  Below the sands are clays from the bottom of Lakes Hitchcock and Hadley, and below the clays are beds of glacial till from glacial periods prior to 20,000 years ago.  Underneath the till is red sandstone, called arkose, part of the New Haven formation, more than 200 million years old, which stretches south into Connecticut.  Finally, below the sandstone is ancient bedrock, a metamorphic rock called schist that developed when 400-million-year-old sediment was heated under the immense pressure of high mountains.

 

Endnotes

[i] Extended quote from Denk, Jeremy. 2012. “Flight of the Concord,” The New Yorker, p. 25.  “”My [Charles] Ives addiction started one summer at music camp, at Mount Holyoke College.  I was twenty and learning his Piano Trio.  There’s an astounding moment in the Trio where the pianist goes off into a blur of sweet and sour notes around a B-flat-major chord.  I knew the moment was important, but I wondered, was my sound too vague or too clear?… One afternoon, the violinist of the group and I were driving off campus and happened to cross the Connecticut River.  Looking out of the window, he said, ‘You should play it like that.’  From the bridge the river seemed impossibly wide, and instead of a single current there seemed to be a million intersecting currents – urgent and lazy rivers within the river, magical pockets of no motion at all.  The late-afternoon light colored the water pink and orange and gold.  It was the most beautiful, patient, meandering multiplicity.  Instantly I knew how to play the passage.  Even better, Ives’s music made me see rivers differently; centuries of classical music had prettified them, ignoring their reality in order to turn them into musical objects. …Ives is different [than Schubert or Wagner].  He gives you crosscurrents, dirt, haze – the disorder of a zillion particles crawling downstream.  His rivers aren’t constrained by human desires and stories; they sing the beauty of their own randomness and drift.”

[ii] This section on the recent geology of the Mill River watershed comes from discussions with John Brady, Professor of Geology, Smith College.  There are no published articles on the Mill River specifically, but both Dr. Brady and his colleague Robert Newton, Smith College Professor of Geology, have extensive field notes on the Smith College area and the Pioneer Valley.  Published sources include the following: Brigham-Grette, Julie et al. “A New Drainage History for Glacial Lake Hitchcock: Varves, Landforms, and Stratigraphy,” North Eastern Friends of the Pleistocene Field Conference, Northampton, June, 2000; Brady, John and Jack Cheney, “Connecticut Valley Field Trip, Keck Symposium, Northampton, 2006.

[iii] There are drill cores at the University of Massachusetts as young as 14,400 YBP, but some of the varves in these cores could be from Lake Hadley, the residual Lake that remained after most of Lake Hitchcock drained.  Noted by John Brady.

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