Date: 2006-06-17
From: Wind Gap

To: Delaware Water Gap
Miles today: 15.4
Weather: overcast clouds

Said my good-byes and thank you to the Schierwagens and again took my next forward step¢¦ Today¢s trek began at PA 33 (980¢) and brought me past Wolf Rocks, Fox Gap at PA 191, Kirkridge Shelter (1,500¢), Totts Gap, Mt. Minsi (1,461¢), Lookout Rock Council Rock and into Delaware Water Gap where I spent the night at the Delaware Presbyterian Church of the Mountain Hostel. There¢s not much to say about DWG ¢ it¢s very small!And, since I don¢t have much to report, this is today¢s lesson on the history, geography and geology the Delaware River Water Gap:A gap or wind gap is a break or pass through the mountains, in this case, the Appalachian Mountains. When a river runs through a gap, the formation can be called a water gap.The Delaware Water Gap is a mountain pass on the border of New Jersey and Pennsylvania, where the Delaware River traverses a large ridge of the Appalachian Mountains. The ridge of the Appalachians that the Delaware crosses is called the Blue Mountains in Pennsylvania and the Kittatinny Ridge in New Jersey. The New Jersey mountain is Mt. Tammany (located in Worthington State Forest), the Pennsylvania mountain is Mt. Minsi. The Appalachian Trail threads the gap, and climbs the Kittatinies by a beautiful stream called Dunnfield Creek.The Delaware River is the only major undammed, free-flowing river east of the Mississippi. It courses for 40 miles through approximately 70,000 acres of recreational land in Pennsylvania and New Jersey and passes between low forested mountains with barely a house in sight. Then it swerves left and right to cut through the mountains on its path to the sea.Delaware Water Gap is a deep, narrow gorge cut by the Delaware River in the Kittatinny Mountains, sixty-five miles west of New York City. This gorge was worn through the solid rock of the mountains hundreds of years ago when the Delaware River was slowly forcing its way to the sea. The gorge is three miles long, with steep, rocky walls on each side from the tops of these mountains to the surface of the river, which at this point is 290' above sea level. Mount Tammany (1,527') is located on the New Jersey side of the gorge and Mount Minis (1,463') on the Pennsylvania side. This area was a popular resort site in the nineteenth century, with large hotels that catered to the upper class. Rock climbing is mostly done on the New Jersey side. Climbers will walk along the cement wall along Rt 80 until they pass the big wall which is metaquartzite with bands of shale. The bands of shale are a between a half inch and four inches thick. There is loose rock which occasionally falls and the sun shines on the wall from 10 am to 3 pm.Starting with Native American legend, there have been many ideas about how the Delaware Water Gap formed. One current theory explains the Gap through a series of processes: continental shift (involving plate tectonics), mountain building (orogeny), erosion, and the "capturing" of rivers and streams. The capturing story begins 420 million years ago when the ancestral continents of North America and Africa collided. The impact caused the earth's crust to rise and mountains to form, including the ancestral Appalachian range, tens of miles east of today's Gap. Streams flowing westward off these mountains eroded their slopes, carrying sand and pebbles west and depositing them in layers. These layers later compacted into erosion-resistant gray sandstone and "conglomerate" rock called the Shawangunk Formation. This rock is the dominant feature of the ridges on either side of the Delaware River today. Over millions of years, many different kinds of rock were laid down on top of the Shawangunk Formation. About 290 million years ago, in an era of mountain building, further pressures crumpled and folded the layers of rock in the area of today's Gap. These layers eroded at different rates: softer limestones and shales eroded more quickly into valleys, while harder sandstone and conglomerate rock remained as mountains like Kittatinny Ridge. The "mountain" part of today's Gap was now essentially in place.A few million years ago (a geological yesterday!) there was a river whose headwaters were around present-day Trenton, and which flowed from there south to the sea. North of Kittatinny Ridge, near today's Water Gap, streams flowed into a second river, which flowed southwest. Over time, the headwaters of the first river eroded their way north to the area of today's Gap. Finding a fault in the rock-probably only a small cleft or fracture-the headwaters worked their way through the ridge to the north side. There they "captured" the flow of the streams and river on the north side of the ridge, making their water flow through the Gap. Cherry Creek in the town of Delaware Water Gap may represent the abandoned bed of this "captured" river. However, at the time the creek "turned around" to flow into the river, the surface of the Delaware River was hundreds of feet higher than it is today. Over time, the cleft in the ridge eroded further from wind, rain, and the constant scraping of sand and rock carried by the river. A water gap was taking shape.Near the recreation area are several other gaps whose formation is related to that of Delaware Water Gap: Culvers Gap, near Newton in New Jersey, and Totts Gap and Fox(town) Gap in Pennsylvania, near the south end of the recreation area, are three gaps nearby. To the south and west in Pennsylvania, along the ridges of the Appalachian Range, are the towns of Wind Gap and Little Gap (where I just spent time with the Schierwagens.) West of Philadelphia near Route 30 is a town named simply Gap.At one time, rivers may have run through these gaps also, and it is possible that the Delaware River has "captured" the rivers in these other gaps as well. When these gaps "dried up," the erosive action of the river stopped, and most of these gaps are much higher (less eroded) than the Water Gap. At the Water Gap, the Delaware River continues to cut into the mountains to the present day.In the 1960s, a dam was almost built upstream of the water gap at Tocks Island. The Delaware Water Gap National Recreation Area was created from the land acquired for the planned reservoir. The beauty of the area around Delaware Water Gap makes it a popular summer resort. I didn't have time to write a short letter, so I wrote a long one instead.   - Mark Twain -