Lehigh River & Canal at Jim Thorpe, PA

Chapter 1 - The Lehigh River Region

What is the source of water for the Lehigh River?

There are three natural sources of water for the Lehigh River. The basic source is water from mountain streams. The area around Gouldsboro, Pennsylvania is a spring flooded wetland. These acres of these marshes drain into tributaries that combine and become the source of the Lehigh River. As the river continues southward, additional mountain streams and wetlands drain into the Lehigh River. Winter snows melting in March and April greatly increase the river's flow in the spring. Rain is the third water source. Spring combinations of melting snow and severe rain, called freshets, were once a source of flooding. These freshets destroyed bridges and dams on the river and flooded Mauch Chunk (now the borough of Jim Thorpe) with up to five feet of water. The Francis E. Walter Dam was built near Blakeslee to control these spring freshets and reduce the danger of flooding. In addition to flood control, this Army Corps of Engineers' dam is responsible for preventing seawater from entering the drinking water supplies in the Philadelphia area, storing water for summer drought control and providing for fishing and boating.

What creates Lehigh River whitewater?

Whitewater gets its name from the color of the tops of waves in rapidly moving water. As the waves pass beyond large rocks, they hit the slower moving water on the far side of the rock and splash upward. The splash is a white colored mixture of air and water.

Whitewater rivers consist of slack water pools and rapids. Both natural dams caused by rock formations and the remains of constructed dams are found along the Lehigh River. The constructed dams were built during the early 1800's to provide deep water for coal carrying river barges.

The dams, eroded by floodwaters over the last 150 years, no longer block the river. Instead, their subsurface remains create slack water pools on the upstream side and whitewater on the downstream side.

What is the origin of the name of the Lehigh River?

At the time Pennsylvania was settled by Europeans, the native people were the Lenni Lenape (Delaware Indians). Many of the names of places in eastern Pennsylvania are derived from names given by the Lenape.

Most settlement of the region was initially along the Delaware River. The Lehigh River flows into the Delaware River at what is now the town of Easton. In the 1600's, it was called the Forks Of The Delaware. The river was originally known by the Lenape name "Lechauwekink", meaning "where there are forks". The Pennsylvania Germans shortened the name to "Lecha" and the English mistranslated it as "Lehigh."

What is the route of the Lehigh River?

The Lehigh River is born as a mountain spring in the Gouldsboro area (about 15 miles southeast of Scranton). It forms the border between Luzerne, Monroe, and Carbon counties as it flows through the hamlets of Clifton, Thornhurst and Stoddartsville and into the Francis E. Walter Dam.

At White Haven, the Lehigh River and its banks become the Lehigh Gorge State Park. Over the next 30 miles, the river flows through a wilderness area that is a haven for whitewater boaters and mountain bikers. Within the boundaries of the Park, access on paved roads is limited to White Haven on the north, the Park Headquarters at Rockport near the center and the Glen Onoko take-out at the south. The Lehigh River exits the Lehigh Gorge State Park north of the town of Jim Thorpe.

From Jim Thorpe to Bowmanstown, the Lehigh River becomes flat water and is enjoyed by summer boaters. If you boat south of Bowmanstown, a dangerous low head dam makes portaging of boats mandatory.

The Lehigh River then crosses the Blue Mountains at the Lehigh Gap near Palmerton. The Blue Mountains separate the Upper Lehigh region from the Lehigh Valley. The Lehigh River continues south through Walnutport and into Allentown. At Allentown, the South Mountain prevents the Lehigh River's southward flow and turns it to the west and into Bethlehem.

At Bethlehem, the Lehigh River's speed continues to slow until it merges with the Delaware River at the dam in Easton. The Delaware River flows south past Trenton, Philadelphia and Wilmington ultimately emptying into the Atlantic Ocean.

What was the origin of the Lehigh River?

Based on discovered coral deposits, approximately 250 million years ago, northeastern Pennsylvania was a tropical inland sea, the Appalachian Sea. During that period, ferns and plants were abundant. It is believed that over the succeeding millions of years, layer upon layer of decaying plant matter was transformed into thick veins of coal.

Geologic studies indicate are that about 100 million years ago, the Lehigh region experienced a series of earthquakes that were responsible for creation of the mountains. These earthquakes generated high pressures which transformed the coal to anthracite, the coral to limestone and the clay to slate. When the mountains were formed in the northern Lehigh region, these minerals were carried to the surface and became accessible for mining.

Within the last 100 thousand years, at least three glaciers advanced to the northern Lehigh. The Blue Mountains formed a southern boundary to this advancement. At the Lehigh Gap, glaciers cut a channel through the mountain range before receding. The receding glaciers left behind deposited Canadian rocks in the river bed. These are called glacial errata.

How far do the Blue Mountains extend?

The Blue Mountains are part of the Appalachian range. In New Jersey, they still use the Lenni Lenape name: Kittatinny (Endless) Mountains. Along the crest of the Appalachian Mountain range is the Appalachian Trail. The Appalachian Trail runs from Maine to Georgia covering about 2,200 miles.

When were the great floods on the Lehigh River?

The legendary floods of January 8,1841, June 5, 1862 and October 4,1869 damaged the Lehigh Canal, bridges across the Lehigh River and homes in the Jim Thorpe area. The crest of the flood waters in Bethlehem, measured about 22 feet above the low water mark. All the original wooden bridges were destroyed in the 1841 flood. Flood damage is now unlikely since construction of the Frances E. Walter Dam.

Continued: Lehigh River & Canal - Chapter 2 - The Native Americans