Saturday, April 15, 2017

PA Muddy Run Park: Following the Coonhound

On this Holy Saturday, a day for contemplation and quiet in the Christian tradition, I took my coonhound for a walk at Muddy Run Park across the river in Lancaster County. Being a coonhound and not of any particular tradition, she was her usual vocal self baying at bounding deer and following her nose across the wooded hills with me hanging on for the ride. So much for contemplative and quiet!

Bug pulls me across the bridge to the woods trails! Follow the nose!
Muddy Run Park is a power company facility that encompasses a large flooded valley that is pumped full of water up from the Susquehanna five hundred feet below. The dam that impounds the reservoir is the longest in Pennsylvania and you can drive across the top and look far across the river to York County from the top. But we're here to hike so no ride across the dam.

The lake is the drowned valley of Muddy Run, once a steep ravine creek.
The woods are beginning to blossom. Black cherries are in their finery with delicate clusters of pinkish white blossoms. Spicebush glows yellow in the old meadow woods. Buds on the blueberry and sassafras are about to burst. Invasive honeysuckle shrubs have already leafed out. Bug rustled up two deer and let out a loud bay that I was sure would flush all of the woods of every living thing. The farside of the hill was old pasture having gone to woods, so I hung on as Bug pulled me over the crest in search of groundhogs and more deer. We found both much to her delight!

Spicebush glow.
Nothing here is pristine or original. When the property was claimed from hard scrabble farmers, most of what is now extensive cherry woods was heavily farmed through the 1950s. Stately sycamores that marked the springhouses of several farms stand now surrounded by mature pioneer forest transitioning to something new. Old apple orchards are dwarfed by locusts and maple. Old farm roads serve as grass paths through glades of spicebush, cherry-birch, black cherry, and pin cherry - all in bloom.  

Cherry woods in bloom.
Cherry trees are the primary pioneer tree of old fields in this part of Pennsylvania. Not too far south, across the Mason-Dixon Line, the primary pioneer is red cedar but no cedars anywhere to be seen in these hills. I could make out old fence lines from where birds perched on wire or oak boards and "planted" straight lines of cherry. Birds are the planters of pioneer cherry woods. 

Old apple trees mark an orchard.
Cherry-birch with sapsucker holes.

Bird-planted cherries along a now gone fence line.

After several more groundhogs and another pair of deer, Bug pulled me over the hill to where the oak woods met the old fields cherry forest. As we followed a grassy path the oaks stood on one side of the farm road while the oaks stood on the other. I could now see the pumped storage reservoir, a long lake that drowns the steep creek valley of Muddy Run. Built by the Philadelphia Power Company in 1968 the lake is drained through a set of powerful turbines at the bottom of the outflow canal back into the Susquehanna. The powerhouse machinery was designed by Westinghouse engineer Eugene Whitney who also designed the giant machinery for the Grand Coulee Dam on the Columbia. Some of the impressive vintage equipment can be seen in front of the Visitor's Center.


Oak woods on the left and cherry woods on the right.

Yellow-blazed lake trail
Up until recently, Muddy Run Park had been completely fenced in to protect the reservoir. This created a big problem for the herd of deer contained inside. Without predators, the herd increased to unhealthy numbers. Even with an annual bow hunt, the herd was browsing the park to nubbins. The fence has since been opened by staff by removing panels of chain link and the deer trails pour through these gaps into the farmland beyond the park. It will take some time for these woods to recover. As we walked along the rocky north slope on the yellow-blazed lake trail, I noticed the heavy browse of the lowbush blueberry. Another pair of bedded deer popped up ahead of us and Bug began to cry her famous deep bay. 

Stilted tree.
The soils on the north slope are very poor. Fallen trees become important sources of nutrients released into the poor soils. As they rot, they often become seed beds for saplings as nurse logs. Once the nurse log rots away, the maturing sapling retains it's nurse tree "stilts" to show that it once wrapped its young roots around and under the log. 

Moss "shadow" of fallen tree.
Quad poplar!
This woods has been worked hard in the past. Plenty of stumps rotting into the rocky subsoil illustrate that the hillside was logged heavily for a long time. Some stumps re-sprouted and developed multi-stemmed trunks. This made for some Holy Saturday contemplation as I looked around and realized how much of the forest had regenerated from fallen trees and cut stumps. 

Stump shadow.
Tree pollen on lake surface.
Muddy Run reservoir.
I couldn't contemplate for long, however, as Bug the coonhound caught scent of something more exciting than deer or groundhogs. I went tripping along her trying to hold tight to the taut leash. She led me straight to the water and jumped in - almost pulling me in with her! All she wanted was a good cool soak after our two hour hike through the woods!

Notes: 

Muddy Run Park is nice place to spend a day or a week. Very nice family-run campground and darn good fishing! The lake, however, is not open for swimming. Unless you are Bug the coonhound.




Monday, April 3, 2017

PA Lock 12 to PA Game Lands #181

I've walked this path many times and was happy to lead a small group from the Philadelphia Chapter of the American Pilgrims on the Camino (APOC). The weather could not have been more perfect for this group of past and future Camino hikers, many of whom drove over an hour to walk this section in the Mason Dixon Trail with me.  In my opinion, this 8 mile section of the MDT is one of the most remote and most beautiful.

The river was rolling today! Snow melt from New York and northern PA. Photo by Kim.

The Susquehanna was thundering over Holtwood Dam. Snow melt from central New York and northern Pennsylvania is raising the river by several feet and that, added to the much needed rain we had last week, made for some pretty rough waters below the dam. Even the ever-present white water kayakers stayed away.  Our hike took us up to the rocky bluff high above the river valley and as far as the eye could see upriver and down, the Susquehanna was fat and fast with gray-green flood water.


Roy, Philly Chapter outings coordinator, loved his first exploration on the MDT.

Spring is here! In the low creek valleys and down along the river banks we saw wildflowers just beginning to bloom. The River Hills area is known nationally for spring wildflower blossoming. People make pilgrimages up many of the remote creek valleys on both sides of the river to witness the week's long event. For most of our hike we had two spectacular steep ravine creeks to ourselves, and when we weren't threading our way through thickets of rhododendron, we were gawking at the beds of bluebells, Dutchman's britches, toothwort, and coltsfoot.

Virginia bluebells.
Dutchman's Britches.
Oak Run, a step ravine creek valley is loaded with waterfalls and wildflowers.
Rocky outcrops at every turn on Oak Run.  Photo by Kim.
The water was pretty high on the ravine creeks, too. At our final creek crossing we had to wet-foot across, boots slung over our shoulders. I noted my FOY Eastern Phoebe, Blue-winged Warbler, and Pine Warbler. A fellow Camino hiker and I exchanged notes about the birds we saw in Spain and what I think was a beech marten. Matt actually snapped a photo of his sighting and had it stored on his phone. It was exactly the white-fronted mustelid that I saw on a stone wall on the Camino Frances, while his sighting happened in a thick forest meadow on the Camino Norte.The marten stood on hind legs to look at him and he captured a perfect picture! 

Wet-foot stream crossing, putting sock and boots back on. Refreshing!
A mile-long slog up the hill to the shuttle cars waiting at the Gamelands parking area was just the huff-and-puff we needed to finish our hike with a flourish on the top of the plateau four miles from the river. Thanks to my hiking partner Kim for helping with the shuttle and for two of her shots taken along the way. Everyone had a great hike and many want to come back to hike more of the Susquehanna's many beautiful trails.



Sunday, March 26, 2017

MD Tuckahoe State Park

My sister Laura and I met at Tuckahoe State Park located mid-way up Maryland's Eastern Shore for a new-to-us loop hike of eight miles along a classic black-water creek. We live several hours apart so our hiking opportunities are not as frequent as we'd like but this was a great spot to meet half way between the Lower Shore and the Lower Susquehanna Valley. I was curious what we'd find on this very early spring day. Only the peepers and leopard frogs are calling in my neck of the woods north of Tuckahoe, so it was a preview (for me) of what will come next week to South-Central Pennsylvania.  

Blue blazes on the east side of the creek, orange blazes on the west side following Pee Wee Trail.

Tuckahoe is unique in that you can hike along hilly terrain for a good workout while enjoying wooded-over Pleistocene sand dunes. The glaciers were north by about a hundred or more miles and never reached this far south, but a cold wind would have been constant, pushing dunes inland with ice-generated weather systems. These dune relics are covered over by loblolly pine, holly, maple, oak, tulip poplar, and hickory. I like to imagine this landscape as Cape Henlopen looks today with its marching dune suffocating the forests along the ocean, but in this case the forest won out, stabilizing the dune system during the interglacial period. Though the Tuckahoe region was never ocean front, it did experience a long period of intergalacial back-flooding when sea levels rose and drowned the Choptank River and all its tributaries including Tuckahoe Creek. 

Quaternary deposits below the dune layer.

All along our hike there were frequent bridge, log, and board crossings over smaller streams. These are incised streams that, like Tuckahoe Creek, are actively down-cutting into the dune formations. At one minor stream crossing we were able to take a peak at an older formation underneath the sand. I'm more familiar with Tertiary formations from my fossil collecting forays on Maryland's Western Shore, so I was surprised to see a familiar face on this side of the Bay!

Cut-leaf toothwort - I usually don't see this blooming until mid-April in my neck of the woods.

Bloodroot

Tuckahoe Creek.

We walked through the Adkins Arboretum trails connected to the blue-blazed Tuckahoe Valley Trail to the east of the main creek and enjoyed stopping to examine the earliest spring tree blossoms including witch hazel and early red maple in the damp woods. The Adkins meadow clearing goat crew was relaxing in the bright and very warm sun. Goats are used to help maintain a system of sand-meadows that trees would otherwise overwhelm. We saw signs of past meadow burns and lots of goat munch as we threaded our way through the Arboretum property. It's a lot of work to keep the trees at bay! Long ago, Native Americans would have maintained the sand meadows with managed burns - just like we do today. But the reason for maintaining the meadows were different then. A healthy meadow produces an abundance of meat, berries, and herbs.  Wild herds of elk and deer would have done the job of goats today, while berries attracted not only people but bears, turkey, and other important animals species. Today we maintain meadows for native plant sanctuaries, pollinators, and bird habitat.

Meadow maintenance goat enjoying the warm sun.

The onset of spring always fascinates me, especially as I continue to investigate how we perceive of time's passing. Humans create structures around our perceptions of time like "four seasons" or phases of the moon. But if we can get out of our own (very limited) way, we can think about time passing differently. The creeks cutting their way down through the ages. The ebb and flow of forests over meadow clearings. These are vast processes that surpass the human-sized parade of seasons and that leave me in awe of Big Time as not just as just a linear trajectory, but as a complex interaction of thousands of small changes in the land. On the way down to meet Laura for today's hike,  I listened to Krista Tippet interview physicist Carlo Rovelli about his new book Seven Brief Lessons on Physics. I actually pulled over to write this quote in the journal I carry in my backpack -

 Physics opens windows through which we see far into the distance. What we see does not cease to astound us. We realize that we are full of prejudices and that our intuitive image of the world is partial, parochial, inadequate.


Spotted turtle, Clemmys guttata

Rovelli and Tippet discussed how we think about time as being "used or wasted" and how utterly helpless we are to understand that "wasted" time in one person's eyes can be critically important creative space for another. A basking painted turtle, tiny and elegant on his sunny log in the woods, may not be thinking about how to solve the world's problems, but this unproductive time (to us) is super-critical to his survival even though he doesn't appear to be doing anything. Consider that for 220 million years turtles have basked in the early season's warming rays, light and heat powering up their metabolism. There are processes invisible to us that have ensured that turtles have been around a long time. 

Tree swallow defending a preferred nest site below his perch.

We enjoy watching the return of migratory birds to our area each spring. The osprey have returned as have the tree swallows. We watched several pair of blue iridescent tree swallows attempt to claim and guard nesting boxes in the meadow. The migration of birds has been going on a very long time and we are privileged to see it happening, marking spring and fall in our human minds. Scott Weidensaul, however, asks us to consider migration  not as distinct events that occur only during these two seasons, but as a continuous process through the year and that have spanned millennia. Tree swallows are pouring north from Central America and Mexico. No border fence or wall can stop them. Their flights are paused briefly by mating and rearing young. When all are able to fly, they gorge on late summer's insects, fattening up for the swing south again.
 

Muskrat digging up tasty new roots.

We visited the visitor center at Adkins Arboretum and watched a muskrat digging up deliciously tender new growth from the marshy pond out front of the building. Smaller than a beaver, the muskrat is considered a delicacy meat on the Eastern Shore and there are local festivals to eat it, though neither Laura or I would ever want to eat one. Their slender tails are more like vertical rudders compared to the flat, horizontal paddle of the beaver's tail. When a muskrat swims, its tail fans it along, side to side, gliding in arcs.

An outdoor classroom built over the muskrat's marsh makes a nice viewing platform - can you see him?

All along our hike we listened to frogs. Leopard frogs growled while spring peepers lit up the forest ponds in a boisterous announcement of spring's arrival. We spotted a wood frog, a young green frog, and later heard the deep bass call of bullfrogs as we crossed Tuckahoe Creek to return along the orange blazed Pee Wee Trail.
 
Young green frog.

There's an equestrian center on the Pee Wee Trail side of the creek, so we encountered horses and their riders a few times. We also met up with two fat-tire bike riders and a trail bike rider. Everyone was courteous on this section of multi-use trail. The west side of the creek is hillier than the east and it is not flat with abundant tree roots and steep climbs in and out of side creeks. I was looking recently at a friend's hiking blog where she hiked this loop with her wheelie-carted German shepherd and though we took a lot of the same pictures (!!) on our two different hikes, but the pictures of her dog negotiating this rugged section of the loop was sweet, if not ambitious! See Notes below for link to her picture-filled blog.


Over Tuckahoe Creek on the footbridge at the halfway point.

The trail undulates up and down near and above the main creek and as we went we saw more signs of previous land use. An old hedge row with a few sections of wire fencing. Some crockery pieces. A foundation with a well hole inside. The land that is now the park was once farmland. Tractor parts, a 1940s era pick-up truck wreck, and an old bike littered the woods.  People can change landscapes by simply changing ownership. Landscapes can change, too, according to natural land managers...

An ambitious beaver project with the lodge just meters away.
These beavers have plans.

Over time the area farms became conservation land and recreational space. Agricultural ground was once coastal plain forest where tree cutters and logging operations thrived. Cleared land could be stumped out and cultivated for crops. Much of that rich soil, however, has ended up in the creek over the last century. Tuckahoe Creek once ran very deep and clear. Now it is shallow and silted in and its flood plains are managed by beavers - nature's greatest engineers. We spotted a lodge but no dams. Maybe they'll come later. When they dam creeks, the back pond becomes a safe predator-free space for a lodge. When the dam breaks and the beaver are gone, a beautiful beaver meadow grows in its place. Trees will eventually fill the meadow. Beavers may return, as they have here. What comes around goes around.


An old bike.

The Pee Wee Trail comes out at a paved road that has the orange blazes along the shoulders. A quick mile took us past the equestrian center then on to the dam and the parking areas. I think next time we'll explore the lakeside trail above where we parked. We were pretty hungry and wanted to get to late lunch before rain started falling. It was very humid as we got back to our cars and rain clouds were building in the west. We drove into beautiful Denton on the Choptank River and listed our sightings for the day as we munched on salad and pizza!

Yellow warbler
Tree Swallow
Robin
Cardinal
Bald Eagle
Osprey
Turkey Vultrure
Downy Woodpecker
Mourning Dove
White-breasted Nuthatch
Great Blue Heron
Spring Peepers
Leopard Frog
Green Frog
Wood Frog
Bullfrog
Beaver (sign)
Muskrat


Sisters on a hike!

Notes:

Here's the transcript of Krista Tippet's interview with Carlo Rovelli that I listened to on the way down to Tuckahoe State Park. From the On Being website: https://onbeing.org/programs/carlo-rovelli-all-reality-is-interaction/

Gone Hikin' Blog post about Tuckahoe State Park hiking with an old pup in a wheelie cart.  http://gonehikin.blogspot.com/search/label/MD%20Tuckahoe%20State%20Park

One of my favorite books, Living on the Wind: Across the Hemisphere with Migratory Birds, by Scott Weidensaul (1999).

Saturday, February 25, 2017

MD/DE - C&D Canal Path End-to-End Hike

Maryland's section of the Chesapeake and Delaware Canal Path

The full length and fully paved Chesapeake and Delaware Canal Recreational Path is now officially open. It starts in Chesapeake City, Maryland, and ends in Delaware City, Delaware, and is mostly very flat, making this a great place to ride bikes or stroll. I walked the full length of 16 miles (some say 17, others say 14, but my GPS said 16) on President's Day in sixty degree weather. We haven't had winter yet. Though wide and deep nowadays to accommodate modern barges and sea-going vessels, it got its start during the golden age of canal building in the 1820s. 

Rt 213 bridge over Chesapeake City.

The canal was put into private service in 1829 to shorten the distance between maritime industries in the Chesapeake Bay with Wilmington and its busy industrial seaport areas.  Built originally for shallow draft barges and sailing ships at ten feet deep with four locks, horses and mules were employed to tow the vessels from one end to other. By 1927 the canal was deepened to 12 feet , widened to 90 feet, and ownership transferred to the U.S. Army Corps of Engineers. Several expansions have occurred since, and today the canal is 27 feet deep and over 450 feet wide to accommodate sea-going vessels to shorten by 300 miles the distance from Baltimore to the Atlantic via the Delaware River. 

Tug pushing a barge.

The expansions of the 1930s triggered studies by U.S. Army Corps of Engineer hydrologists who were interested in how water dynamics had been affected between the Delaware and Chesapeake. They discovered that there was a net flow of water from the Chesapeake to the Delaware, and that even with the daily oscillation of tides, there was always more water flowing east than west. My walk took about five hours (including a snack break) and I watched the canal flowing reliably eastward even with an incoming high tide that raised the level of the canal but did not affect its flow. When I returned home, I checked my observations against a 1971 paper by Pritchard and Cronin, University of Maryland Chesapeake Biological Lab, that used the original 1938 report to compare how hydrology had been affected by the most recent expansions.

The iconic Army Corps of Engineers trestle lift bridge.

Cronin, the hydrologist, measured an increased volume rate of flow from the Chesapeake to the Delaware at 2.70 times the rate measured by the 1938 study. In addition he noted increased velocities of water moving east. Averaging against the annual tidal variations and seasonal adjustments, he estimated that the current had increased 1.7 times faster with the canal at twenty-seven feet deep compared to twelve feet in 1938. Pritchard, the biologist, wondered how these changes affected the estuarine ecologies of the Delaware and Chesapeake. He measured salinity gradients, turbulence, and conducted biological surveys of the canal at both ends and in its mid-section. Would the canal serve as a barrier or a boon to fish species and populations? 

Ocean-going ship passes under the Rt 301 bridge.

They discovered large numbers of striped bass eggs and larvae in the canal as well as an increased number of spring spawning fish including perch, shad, and spot that swam "upstream" against the new currents from the Delaware. The canal had become an attraction to migratory fish, benefiting the Upper Chesapeake.  Pritchard and Cronin noted that the canal had become a rather dramatic example of an engineering activity which has created a new biological environment as well as an improved shipping route."  In the years since this paper, a thriving striped bass fishery has developed as a result. The canal expansion, which had initially worried local environmentalists, had resulted in an increase in fish species and numbers at both ends of the canal, while providing a new migratory route connecting the two bodies of water.

The Ridge, a natural hill structure about two miles in width is bisected by the canal.

The C&D is a dynamic system both for estuarine life and for management. The U.S. Army Corps of Engineers must constantly assess the canal for shoaling, the accumulation of bottom mud and sand that form ship-stopping banks. This requires periodic maintenance dredging which happens every few years, and the spoils can be a lot of fun to pick through for fossils. Though the canal path does not cross through any of the dredge dump areas, it is an easy side trip by car to reach them. Keep in mind that between dredging, these piles are picked over by fellow fossil enthusiasts but word of fresh material travels quickly. We've found come impressive Cretaceous oyster shells, belemnites, and small shark teeth. During the time these deposits were forming hadrosaurs and mosasaurs were common.

Map courtesy of The Fossil Guy, http://www.fossilguy.com/sites/canal/
 
Though the canal path for most of its length is flat, there is one two-mile stretch of hilly terrain that bears some mention - and some time to explore. "The Ridge" as a local hiker pointed out to me, is a low set of hills made of unconsolidated Cretaceous sands and gravels where vegetation is critical to the maintenance of the canal. These hills, once high sand dunes and wind-driven features, still retain their open coastal profiles for anyone wanting to imagine the period of opening oceans and rising sea levels. Covered in a beautiful forest of pitch pine and coastal plain hardwoods, the ridge area proved the biggest challenge to canal builders as time when forest cover was scant and tons of loose material would cascade in dangerous "sand-falls" into the work area. Known as the Deep Cut where canal builders encountered The Ridge, three and half million cubic yards of material was removed from the sand hills. As they worked to remove the sand from what would be the canal basin, tons of the material slid in from the sides. It was dangerous and frustrating work.

Aerial crossing for natural gas pipelines.

Today the area around Lums Pond State Park is preserved and open for the public to explore as well as areas west of Rt 1 bridge. Various dirt roads lead from the main roads in to the sand hills with parking areas, sometimes trashed, that lead to trails and open areas to go birding and plant gazing. It's a tough area to make home as the ground is loose and shifting. "Be prepared for lots of mud and the possibility of getting your car stuck," said my hiking friend, Sarah. Best to check this out during a dry period, eh? Meanwhile along the path, a steady bank of locust trees provided a large local black vulture population with plenty of places to soak up the warm afternoon sun. I happen to love vultures (sometimes to the point of distraction) so as I stood admiring them, my hiking friend decided to turn around and head back to Chesapeake City. Soon I was at the boundary with Lums Pond that has a beautiful new parking area, picnic benches, and a (locked!) bathroom.

Lots of black vultures in trees along the path.
Bridge gazing! Wow! Rt. 1 and St. Georges Bridges.

I was bridge-gazing all along the path. These big bridges soar high over the canal to give room to the huge ocean-going ships. They really are works of art in engineering and design, each one a little different with its own unique profile and character. High level traffic bridges have their own followers and I met two men on bikes who were photographing the bridges as they went. I learned way more than I ever though possible about high level engineering. Some people chase trains. These guys find high bridges and are really excited with them. They were really about adding the Summit Bridge, the U.S.A.C.E. trestle bridge, and Reedy Point Bridge to their photo-list. "Being able to bike under them is a thrill!" one biker told me. My only stop of the hike came at the Summit North Marina where I watched the University of Delaware Research Vessel, Joanne Daiber, undergo an inspection before returning her t the water for the new season.

University of Delaware R/V Joanne Daiber.
Marina store and picnic area rest stop.

I stopped in at the just-opened marina store for a snack and drink. The counter clerk was busy restocking a shelf of gum and candy bars. I asked her about the new canal path and what it might mean for business. She grinned ear-to-ear. "It's been great already - even before they completed the whole tract - but now it will be even better." She told me about how many bike riders make this their halfway stop on the end-to-end ride. I told her I was walking end-to-end and she looked at me incredulously. "You are walking it? The whole thing? Wow. I guess we need to think about hikers too!"  This is an important point - the economic benefit of paths and trails is often overlooked when our "so-called" political and policy leadership debates the merit of funding and protecting outdoor recreation sites, conservation lands, and open space. A six-billion dollar recreational/outdoor industry that continues to grow in this country is not to be ignored. The canal path alone, according to the store clerk, a University of Delaware graduate student, will generate interests in new businesses in canal path towns. Given its proximity to large areas of the Mid-Atlantic's population, she said, it's really an opportunity for new lodging, eateries, bike rentals, and parks. 

Welcome to Delaware City!

Another hour and I was entering Delaware City where my daughter and her family were meeting me for dinner and a ride back to Chesapeake City where I left my car.  The newly restored promenade path blended perfectly with the canal path and I walked along a remnant of the old canal that splits from the main C&D. The old town was beautiful in the low February sun and soon I was facing the broad Delaware River facing New Jersey with Pea Patch Island and its impressive fort in between. 

Delaware City - a beautiful and active old canal town.
The town has invested seriously in its waterfront park and main street. The American Birding Association has moved its national headquarters here. Fort Delaware State Park maintains a scenic ferry tour to the island in season at the end of the old canal and the south side of the old canal is left to bird-filled marshes. My family arrived and we decided to have dinner at the Delaware City Hotel where we sat in an 1820s hotel pub for seafood and hush puppies. Perfect ending to a long day on the canal path.
 
 
Notes:

The canal path goes by several names along its length: The Ben Cardin Trail in Chesapeake City, Maryland, C&D Recreational Trail between the terminus towns, and the Michael Castle Trail in Delaware City. Large parts of the canal area are protected as the C&D Canal Wildlife Area, under the management of the Delaware Department of Fish and Wildlife. http://www.dnrec.delaware.gov/fw/Hunting/Documents/WMA%20Maps%202016/CD%20Canal%20-%20Castle%20Trail.pdf

 Donald Pritchard and L. Eugene Cronin presented their paper "Chesapeake and Delaware Canal Affects Environment," at the American Society of Civil Engineers Conference for National Water Resources in 1971.  http://aquaticcommons.org/4513/1/447.pdf

The Fossil Guy web page gives the local fossil hunter plenty leads for where and how to search for C&D Canal dredge spoil fossils. http://www.fossilguy.com/sites/canal/