Silver Lake Park
- Nature Acres
Silver Lake Nature Center
We begin with a stop at the center of Silver Lake Park, Silver Lake Nature Center. This 235-acre complex is unique to Pennsylvania in that it harbors the best-protected Coastal Plain Forest left in the state. It is part of the 460-acre park and Silver Lake which is the terminus of the Mill Creek, Queen Anne Creek, and the Black Ditch Creek Watershed.
The main building houses a multipurpose auditorium, exhibit room depicting that which is unique to the park, offices, the Barnswallow Gift Shop, and a reference library. Immediately outside the building is a large meadow. Nearby, a 60-person amphitheater is designed for campfires and shows. Groups, private or public, often use a nearby picnic pavilion.
The mission statement of the Nature Center deals in providing the public an opportunity to learn about the uniqueness of Silver Lake Park, the natural environment, and nature-related crafts. It is also the mission to provide space for activities leading to the enjoyment of the outdoors in an environmentally friendly manner. The last part of the mission statement deals with promoting the preservation and research of the unique historical and natural heritage of the surrounding community, especially species of concern.
The function of the center is to provide environmental sessions for the young and young at heart. Individuals, families, schools, and organizations are offered classes on a wide range of topics. Off-site activities give groups or individuals a chance to study and learn about other types of ecological habitats. Another function of the center is the mutual cooperation that has been established over the years with other scientific and environmental organizations like :
- Association of Nature Center Administrators
- Bucks County Audubon Society
- Pennsylvania Department of Environmental Resources
- Pennsylvania Alliance for Environmental Education
- Philadelphia Zoological Society
- Sierra Club
- Other nature centers in and out of Bucks County
The center also provides consultation and advisory services to the general public on a variety of environmental matters. Volunteers make up a large portion of the dedicated workers who assist with trail maintenance, fundraising, developing public workshops, and assisting with building operations.
The management of the center is led by a group of professional naturalists, under the guidance of the County, who dedicate themselves to understanding and interpreting this valuable piece of land. They coordinate with the County and other outside agencies to provide a clean, safe, diverse, enjoyable, and educational facility through development of activities, without discrimination. The Naturalist is Bob Mercer who is the featured employee in this newsletter. Mr. Mercer has a trained staff that is funded either by the Department of Parks and Recreation or the Friends of Silver Lake Nature Center.
This area represents a geologic zone referred to as the Coastal Plain. Let's go back a bit in history to find out how Silver lake came to be.
During the last glacial period, the oceans were about 100 miles further inland. Much of our water was contained in ice. The glaciers came down as far as Easton which is about 60 river miles from Bristol. Along their path, they scraped, plucked, smashed and ground different types and sizes of rocks. When the glaciers melted, water flowed into the Delaware River, increasing its size tremendously. Rocks floating down the river were chipped along their edges, making them rounded in shape. This mass of water encountered a dam, thereby spilling over into the areas we now call Falls Township and Trenton. Once over this obstacle, the water flow decreased and spread over a large area. Many of the rocks transported along the way found a new home. If you pick up rocks in Silver Lake Park, you will notice that they are rounded, having been taken from their unknown origin and laid to rest in Lower Buck County. Also noticeable are the varied colors of rocks.
Due to the fact that these rocks had very diverse origins, many types of minerals are now found in our soil. Lower Bucks County is reputed to have some of the richest soil in the state. Unfortunately, this has also aided in the construction industry. This prime soil has sprouted houses as well as farmlands. The housing developments seem to have won. The type of soil found in Silver Lake Park, is the reason it is so highly protected as a Coastal Plain Woodland. If you visit, you'll notice the relatively flat terrain within the park boundaries. The elevation varies from 18 feet above sea level to only 34 feet.
This type of geology makes the park unique, being reflected in the flora and fauna. Pennsylvanian rare or endangered species are also located here. Many of the plants and animals are more likely to be found in the south like the Magnolia, Willow Oak, Sweet Gum, Red Bellied Turtle, and the Southern Leopard Frog. In contrast, there are few northern species. Each of the Walnut trees were planted and you will not find any Hickory trees, normally common in Pennsylvania.
Records indicate that Silver Lake appeared in its present location around 1701. It was originally man-made as a pond in 1687 when a dam was placed on the Otter Creek to provide power for the mills in Bristol. The "Mill Pond" grew and incorporated the Adams Hollow Creek, eventually reaching in size between 250-300 acres. Over the years the lake filled in with mud and vegetation, thus becoming a marsh. The present day marshes at Silver Lake were once part of the original lake.
Standing in the marshes, you may notice the rust colored water. During the period of the early settlers, this water was referred to as "that nasty water". In 1773, Dr. Rush began recommending that people bath in the water as a cure for many diseases. These baths were completed in 1801, hence the name Bath Road. These baths were located near the present day hospital site. The attraction of these baths made Bristol quite the resort town. Eventually though, mineral springs found in Saratoga, New York, quickly replaced their popularity, especially once the train lines were extended into Saratoga.
By the 1920's, the lake scarcely had any open water. In 1938, the Pennsylvania Fish Commission purchased the lake and marked the boundary with a square stone having a small hole at the top. It was at this time that the Public Works Administration (PWA) began work on the present lake, by then called Silver Lake. Most of the work was done by hand and the current picnic grounds are the dry land created by hand-dredging the lake.
It took over 300 men to physically dig out the lake. As they were digging, oak tree trunks dating 200 to 300 years were unearthed. From this, we can deduct that the land that is now a lake was once a mature forest. As you walk through the forests, you'll notice that they are surrounded by marshes. The forests were actually islands in the lake at one time.
Route 13 Basin
In the 1940's, when Route 13 was built, the lake was to undergo another change. The southernmost section was filled by removing an island, using the soil as a fill. The lake has remained the same in shape, since then. In 1986, it was again dredged. Only 2/3 of it was dredged due to lack of money. Its depth was only an average of 18 inches. The remainder was dredged in 1994 bringing the depth to a mere 5 feet.
Purchasing of the Property by Bucks County
The Bucks County Department of Parks and Recreation purchased the lake in 1957 for the sum of $1, from the Pennsylvania Fish Commission. The surrounding land owners were bought out during the 1960s. Since then, the staff and volunteers of the Nature Center have managed the vegetation in order to maintain a healthy diversity of habitats.
In 1953, a gravel pit for the construction of the Pennsylvania Turnpike filled with water, forming a lake. At that time and for years to come, it was called Langenfelder Lake after the contractor. Being that the contractor was not obligated to enhance the finished lake for public use, it has a square shape with steep sides.
In 1959, the township attempted to construct a small swimming pool adjacent to the north side of the lake. The project failed due to non-sufficient funding. A pool was eventually built but not at that site. The lake was renamed Magnolia Lake in 1964 when the Bucks County Park Board picked a "name the lake" winner. Randy Vogenberg, the winner, was awarded a season pass to the Silver Lake Pool.
Despite local rumors, this lake was never more than 18 feet deep. In 1985, the stream channel from the Mill Creek was routed directly into Magnolia Lake to trap sediment. It is now approximately 35 acres in size and part of the Mill Creek Valley System.
As part of the Silver Lake Nature Center, situated directly across the street, Delhaas Woods is a 175-acre parcel of woodland with nature trails. This parcel was recognized by the Eastern Pennsylvania Chapter of the Nature Conservancy as the "best remaining portion of Coastal Plain Woodlands within the State of Pennsylvania". During WWII, ammunition storage buildings were constructed and the land cleared. After these had been deserted, PECO Energy installed a high tension corridor directly through the middle of the parcel. During the "energy crisis" of the 1970's, the previous landowner removed almost all of the oak trees (except the Willow Oaks). The final insult was unscrupulous contractors who used the power line access as their personal dump site.
Around 1985, the Eastern Pennsylvania Chapter of The Nature Conservancy purchased a 90-acre parcel from a consortium of land speculators who had anticipated the woods being used for either industry or as part of I-95 connection. The parcel was given to the Bucks County Department of Parks and Recreation to manage as part of the Silver Lake Nature Center. In 1987, with assistance from The Nature Conservancy, a parcel of land about 8 acres was purchased from a developer. This parcel made a direct though very thin link between the nature center property and Delhaas Woods. In 1994, once again with legal assistance from The Nature Conservancy, an additional 75 acres was purchased, adding significantly to the size of the corridor and reducing the threat of encroachment.
Once purchased, Bucks County coordinated a series of clean-ups, eventually removing over 200 tons of trash. Trails were installed to provide public access from the nature center building area. Most recently, an effort to route a highway through Delhaas Woods was defeated.
Nature in Silver Lake Park
Delhaas Woods contains 4 major communities: the Coastal Plain Forest, Meadows, Unglaciated Bog, and Pond.
Coastal Plain Forest
In the Coastal Plain Forest, the canopy consists mainly of Sweet Gum trees, Red Maple, Black Gum and Pin Oak along with a few White Oak, Red Oak, and Willow Oak. There is also a scattering of Hickory, Ash, Silver Maple, Big-Toothed Aspen, and Sycamore. Exotic trees include Norway Maple and the Princess Tree.
The understory includes species such as Sassafras, Sweet Bay, Umbrella Magnolia and (lingering) Crabapples. The shrub layer is mostly Southern Arrowwood, Spicebush, Sweet Pepperbush, Fetterbush, Highbush Blueberry, Poison Ivy, Virginia Creeper, Pussy Willow, American Holly, Winterberry, Bittersweet, Grapes, Black Huckleberry, and Swamp Azalea.
The meadows were created as a result of power lines being cleared. They consist of wet and dry meadows that provide refuge for a number of plant species on the Pennsylvania Species of Special Concern list. More notably the Maryland Meadow Beauty, New York Asters, Bushy Bluestem, Slender Sea Oats, and the Atlantic Blue-Eyed Grass.
The third community, Unglaciated Bog, is also considered a Pennsylvania Community of Special Concern. Contained within are some of the plant species listed above as well as Sphagnum.
The fourth community is the Vernal (spring) Ponds. These are scattered throughout the woodlands. These provide excellent breeding grounds for frogs and toads. Due to its small size, Delhaas Woods is not noted for its animal species.
The Nature Center grounds have about 4.5 miles of Nature Trails which are routed through or near the various habitats. The grounds are maintained to enhance the diversity of plant and animal life. The habitats include the above at Delhaas Woods along with Lake, Marshes, and Fields. Protected within the park are 22 Pennsylvania Species of Special Concern. Silver Lake provides refuge for the Redbelly Turtle while the marsh is home for the Coastal Plain Leopard Frog.
Species of Special Concerns
Species of Special Concern found at the Nature Center include the following:
- American Holly
- Atlantic Blue-Eyed Grass
- Bushy Bluestem
- Button Sedge
- Coast Violet
- Forked Rush
- Fringed Paspalum
- Golden Hedge-hyssop
- Maryland Meadow Beauty
- Net-vein Chair-Fern
- New York Aster
- Possumhaw Viburnum
- Slender Sea-Oats
- Soapwort Gentian
- Spotted Smartweed
- Stout Smartweed
- Umbrella Magnolia
- Willow Oak