Geomorphology of Trenton Falls


Prospect Falls, Prospect New York


Modern Geographic and Geologic Setting:



Village (Morgan's Mill Dam) Falls

Location: NY State Dam and Water Diversion Lock near the village of Trenton Falls, New York.

Description: This is a view looking upstream toward the Trenton Falls Gorge. Visible in the foreground and left side of the photograph are the dam and water diversion lock used to divert water to the Erie Canal. This was once the site of Morgan's Mill Dam, which was used for running the old mills at Trenton Falls village.

Most notably however, the strata at the base of Trenton Falls gorge shown in the foreground at right, are a few heavy ledges of lower Trenton Limestones. Unfortunately these rocks are poorly exposed today, mostly due to the construction of bank stabilization features including crushed stone seen in the background and lush wooded growth. Based on the desciptions of early geologists (White, Prosser, Miller, Raymond) and based on projection of stratigraphic thicknesses from nearby areas, it appears that the upper portions of the Kings Falls Formation compose the few feet of heavy-ledged limestones capping the village falls as shown here. Historically this small falls, the most downstream of the section, was also called Mill Dam because of a series of mills built on the site in the early to mid 1800's. (back to orthophoto)








above: "Village Fall"

Image from: N.P. Willis, "Trenton Falls, Picturesque and Descriptive," 1868


The "Narrows"

Location: Base of Trenton Falls gorge: view out of the narrows.

Description: This view is near the lower end of the Narrows with looking downstream toward the power generation facility as seen in the background to the right. Just upstream from the outlet of Trenton Falls gorge, deeply incised, steep valley walls provide the first wonderfully exposed succession of limestone strata beginning in the Sugar River Formation. This unit is well developed here and although its basal contact with the underlying Kings Falls Formation is not visible, several meters of fossiliferous limestones are exposed along the length of "the Narrows" up to the base of Sherman Falls.

Historically, this region of the gorge was called the "Cascade of the Alhambra" by the first proprietor of the Trenton Falls resort. The deeply incised and nearly vertical chasm walls owe their character, at least in part, to prominent north by northeast to south by southwest bedrock joint sets. (back to orthophoto)





above: "Cascade of the Alhambra"

Image from: N.P. Willis, "Trenton Falls, Picturesque and Descriptive," 1868

left: photograph by Tom Whiteley


Sherman Fall

Location: Trenton Falls gorge: upstream from the narrows looking north.

Description: Sherman Falls, the namesake of the first private owner of the property John Sherman, was purchased along with 60 acres of land in the vicinity of Trenton Falls from the Holland Land Company in 1822. Sherman Falls, with a measured height of nearly 33 feet, marks the first of the largest group of waterfalls on West Canada Creek.

This lowermost falls exhibits a nearly vertical drop and when water runoff is at its highest volumes, as in the spring, the water tends to shoot out horizontally a good distance from the face of the falls. It is this tendency of the water to "leap" from the falls that first moved the Iroquois Indian tribes in the region to call this place Kuyahoora, literally the place of "leaping water".

Stratigraphically, the contact of the upper member of the Sugar River Formation, the Rathbun member, and the overlying Poland member of the Denley Formation occurs several meters below the cap of the falls. Several important features to note include the high west wall of the gorge at this section. This nearly vertical wall, somewhat difficult to measure, represents the most continuous outcrop section in the gorge. In addition, several recessive weathering notches are observable both below the lip of the falls and again in the highwall above. These notches are altered volcanic ash layers that prove to be very useful in correlation studies. (back to orthophoto)





above: "Sherman Fall"

Image from: N.P. Willis, "Trenton Falls, Picturesque and Descriptive," 1868


left: photograph by Tom Whiteley


Lower High Falls

Location: Trenton Falls gorge: looking northeast toward Lower High Falls (in the immediate foreground), with Upper High Falls in the background.

Description: The largest set of cataracts at Trenton Falls is made up of a lower and upper set of falls, thus resulting in their designation as "High Falls." The Lower High Falls makes up the largest vertical drop in the gorge, although not in a single face as at Sherman Falls just downstream. Instead, a series of smaller cascading waterfalls drop approximately 100 feet from the top to the base.

Of all the falls in the gorge, this sibling pair of falls are perhaps the most stunning set of falls in the chasm. During the "Golden Era" of Trenton Falls, this set of cascades were more often illustrated in photographs, paintings and drawings than any other of the falls.

Stratigraphically the limestones in this interval show the transition out of the lower Denley Limestone into its upper half. The lack of thick compact bioclastic limestones, such as those seen at the cap of Sherman Falls below, combined with the argillaceous composition of the upper limestones, contributes to the cascading nature of the falls. Small-scale changes in the composition of limestones of the capping beds accentuate the cascades, which result as a series of small drops. (back to orthophoto)






left: "High Fall"

Image from: N.P. Willis, "Trenton Falls, Picturesque and Descriptive," 1868




Upper High Falls

Location: Trenton Falls Gorge: Looking North toward Upper High Falls.

Description: The second part of High Falls, or Upper High Falls, does not drop nearly as much as its lower counterpart; however, it does make the second largest drop in the gorge. Upper High Falls descends over a vertical face of approximately 40 feet. While the face of this falls presents a stunning waterfall, during low flow periods, an offset of nearly 15 feet(?) is noticeable between the west and east sides of the fall face. This offset is the result of a normal fault which has resulted in the down-drop of the western side relative to the eastern face. Stratigraphically, the base of Upper High Falls marks the top of the Denley Formation. This contact is demarcated at the position of a pronounced K-bentonite bed termed the High-Falls K-bentonite. The overlying Rust Formation (Mill Dam Member) composes the compact dense bioclastic grainstones that make up the face and cap of the falls. (back to orthophoto)




above: "Part of High Falls"

Image from: N.P. Willis, "Trenton Falls, Picturesque and Descriptive," 1868


left: photograph by Tom Whiteley


(Upper or Squire's) Mill Dam Fall

Location: Trenton Falls gorge: looking north at Mill Dam Falls.

Description: The uppermost falls within the main gorge reveals more Trenton Limestones. In this case, the set of falls known today as Mill Dam Falls is composed of a fairly coarse grained bioclastic limestone. Due to its resistant weathering, it forms a fairly flat linear bench that extends laterally away from gorge. The topographic expression of these limestones aided earlier settlers in gaining access to the gorge, and they found this location to be the most suitable for the construction of grist mills. A mill dam was first constructed in the early 1800's at this location in order to supply necessary water power for the purpose of milling flour and other products. Because of the relatively gentle incline into this section of the gorge, goods were easily transported in and out.

In addition to its utilization for wagon roads, this flat region also made a relatively gentle incline for the construction of the New York Central and Hudson River Railroad that crossed West Canada Creek at this point. During its time of greatest prosperity, this rail brought thousands of visitors each year from New York City through Trenton Falls. Many were frequent visitors to the Trenton Falls resort known as Moore's Hotel.

Today, the same spot is utilized by the Niagara Mohawk Power Corporation (owned by Reliant Energy) for the generation of electrical power. The Mill Dam Falls is located slightly below the base of the power dam, and still shows nearly 14 feet of vertical relief. (back to orthophoto)






above: photograph by Tom Whiteley (view from the West)


left: "Part of High Falls"

Image from: N.P. Willis, "Trenton Falls, Picturesque and Descriptive," 1868



Power Dam Spillway

Location: Trenton Falls gorge: looking northeast at hydro-dam and spillway.

Description: Near the end of the 1800's, the number of visitors to Trenton Falls had dwindled due to the increased popularity and development of Niagara Falls. By the close of the century, Moore's Hotel and property were acquired by the Utica Electric Light and Power Company and construction of a dam was commenced. Due to the completion of this dam and power plant in 1901, the region immediately upstream was flooded, including the area called Rocky Heart.

In an attempt to engineer for flood control and to divert flow around the main dam, a spillway was blasted out of the eastern rock face just above Mill Dam Falls. This spillway now exposes the same stratigraphic interval once exposed in the floor of the gorge now flooded. Much natural scenery was lost due to this construction, but the majority of the stratigraphic succession is preserved and better exposed in the Spillway. The Spillway Member and the Prospect Quarry Member of the Rust Formation and the overlying Steuben Formation, are exposed here. (back to orthophoto)



above: View north in the spillway, showing the hydro-dam pinnacle and channel.

photograph by Tom Whiteley


left: View northeast above Mill Dam showing the spillway, and the hydro-dam spillway channel.

photograph by Tom Whiteley


Rocky Heart

Location: Trenton Falls gorge, above Mill Dam Fall looking northwest.

Description: Prior to the construction of the hydro-electric dam, West Canada Creek, similar to the narrows below, was narrow and restricted in its course. From this point upstream toward Remsen, West Canada Creek was relatively steep and waters were especially turbulent and produced substantial eddies. These eddies helped to carve out a number of semi-circular potholes. Because some were wide at the upstream end and narrower near the downstream end these features were sometimes heart shaped. Therefore this uppermost set of cascades was historically known as Rocky Heart.

Unfortunately this area is now flooded by construction of the hydroelectric dam in this region of the gorge. (back to orthophoto)


above: "Rocky Heart"

Image from: N.P. Willis, "Trenton Falls, Picturesque and Descriptive," 1868


left: photograph by Carlton E. Brett


Prospect Quarry

Location: West side of west Canada Creek about 0.5 mile south of Prospect.

Description: Beginning early in the history of Trenton Falls, a number of small family farm quarries were operated to provide foundation stone, agricultural lime and mortar. Most likely the commercially operated quarry on this site is an expanded portion of one of these older family run quarries. In 1945, when this region was mapped by the USGS for production of their 7.5' quadrangle maps, a small quarry was in operation close to the stream bed. Today the quarry has expanded and opened larger pits to the south and south west of the old pit. One such pit is seen in the foreground of the above photo. (back to orthophoto)


Prospect Falls

Location: Trenton Falls gorge, at Prospect Falls just upstream from Military Bridge over West Canada Creek.

Description: Northerly view downstream from Prospect Falls toward the Military Bridge above. In addition to the spectacular exposures along the main gorge of Trenton Falls, this upstream addition is equally scenic and interesting for its geology. Prior to the construction of the hydro-dam at Mill Dam Falls, an early attempt was made to convert this segment of West Canada Creek for production of hydroelectric power. Fortunately, the plans fell through and the wonderfully complex strata geometries are still exposed in this location. (back to orthophoto)




Prospect Falls

photography by Tom Whiteley





© 2004 President and Fellows of Harvard College