Hatfield Swamp facts for kids

Hatfield Swamp is a large freshwater wetland area in New Jersey, USA. It acts like a "second bank" for the Passaic River, located between Morris and Essex counties. It's a unique natural space with a rich history and interesting wildlife.

How Hatfield Swamp Formed: Geology

Millions of years ago, the land where Hatfield Swamp now sits was part of a huge crack in the Earth's crust. This crack formed when the North American continent started to pull away from Africa. Over time, this valley filled with layers of red dirt and hard, cooled lava rock.

Later, about 20,000 years ago, a giant sheet of ice called the Wisconsin Glacier covered the area. This glacier was part of the last ice age. As it moved, it pushed a lot of rocks and dirt, blocking the path of the ancient Passaic River.

When the glacier melted, water got trapped behind the Watchung Mountains, which are the hard lava rock ridges. This created a huge body of water called Glacial Lake Passaic. After thousands of years, this big lake slowly drained away. What was left behind were many swamps, including Hatfield Swamp, where different kinds of trees began to grow.

Where is Hatfield Swamp? Geography

Hatfield Swamp is located in northern New Jersey. It covers about 2,500 acres (10 km²), which is a very large area!

Several rivers flow into and through the swamp. The Whippany River flows into the Rockaway River at the western side. The Rockaway River then travels a short distance before joining the Passaic River near the center of the swamp.

The land in the swamp is quite flat, ranging from about 180 feet (55 m) to 160 feet (49 m) above sea level.

History of the Swamp

The swamp gets its name from a man named Cornelius Hetfield. He owned and ran a mill in the area before the American Revolution. During the war, Hetfield was a Loyalist, meaning he supported the British king. Because of this, his property was taken by the American side and sold to Cyrus Crane.

Years later, after a family member named Herbert Crane passed away in the 1960s, the old mill was taken apart. It was then moved to Allaire State Park in Monmouth County, New Jersey, where it can still be seen today.

Wildlife and Plants

Hatfield Swamp often floods several times a year. This can happen from heavy rain, melting snow in the spring, or even hurricanes passing through. Because of this frequent flooding, it's a tough place for many mammals to live. Animals like deer, raccoons, possums, skunks, and foxes usually stay on the edges of the swamp where the ground is higher and drier.

Muskrats, which are small rodents that live near water, have a low population in the swamp. This is because the flooding fills their dens with water. Also, there aren't many of the specific plants that muskrats like to eat. While the three rivers that flow into the swamp used to be very polluted, they have gotten cleaner. However, some dirty substances still remain in the soil and water, which can affect the muskrats.

The swamp is also a resting spot for waterfowl (birds that live near water) during their autumn migration. They stop here to rest before continuing their journey south.

The Rockaway River and Whippany River, which flow through the swamp, are home to fish like carp and catfish.

The swamp has a northern deciduous forest, which means the trees lose their leaves in the fall. You can find different types of oaks, maples, sweet gum, and elm trees here. Most of the trees are not very thick, usually between six and ten inches wide. Some can grow up to twenty inches. The constant flooding makes it hard for hardwood trees to grow very large.

Hiking and Exploring

Hatfield Swamp is part of West Essex Park. It has many trails that are open to the public for hiking. Since the land is very flat, hiking here is quite easy and enjoyable.

Groups like the Essex County Chapter of the Sierra Club and the New Jersey Audubon Society lead trips through the swamp all year long. These trips are a great way to learn about the area's nature. You can find information about these trips at the Essex County Environmental Center.