Gaps of the Allegheny

The gaps, formed by small streams, provide several usable incline planes, or ramps, connecting the eastern river valley lowlands to the highlands atop the plateau to the west and north, that would otherwise have been unnavigable by animal powered wagons before the mid-1930s.

Traversing the line of the Alleghenies southward, the eye notes first the break in the wall at the Delaware Water Gap, and then that long arm of the Susquehanna, the Juniata, reaching out through dark Kittanning Gorge to its silver playmate, the dancing Conemaugh.

Here amid its leafy aisles ran the brown and red Kittanning Trail, the main route of the Pennsylvania traders from the rich region of York, Lancaster, and Chambersburg.

Beyond, to the west, the fingertips of the Potomac interlocked closely with the Monongahela and Youghiogheny, and through this network of mountain and river valley, by the "Shades of Death" and Great Meadows, coiled Nemacolin's Path to the Ohio.

The modern term of art, the Allegheny Front, was coined by physical geologists and other earth scientists interested in geomorphology reasoning out the processes that make one landscape terrain different from another in time, cause and space.

The geology of the curious ridge and valley formations are the remnants of an ancient fold-and-thrust belt, west of the mountain core that formed in the Alleghenian orogeny (Stanley, 421–2).

The evidence points to a wearing down of the entire region (the original mountains) to a low level with little relief, so that major rivers were flowing in unconsolidated sediments that were unaffected by the underlying rock structure.

On the ridges the forest growth was lightest and there was little obstruction from fallen timber; rain and frost caused the least damage by erosion; and the winds swept the trails clear of leaves in summer and of snow in winter.

Here, high up in the sun, where the outlook was unobstructed and signal fires could be seen from every direction, on the longest watersheds, curving around river and swamp, ran the earliest travel routes of the aboriginal inhabitants and of their successors, the red men of historic times.

Right up until the engineering projects that began with the political movement to connect cities and towns with roads better than dirt tracks in the 1920s, there simply were no ways in most areas to transit the barrier of these mountains without well developed wilderness skills.

Examination of the topology however shows that notch leads to a series of climbable traverses and was quite possibly the route of choice for wagons climbing toward the gently rolling oddly folded hill country summit and divide near the source of Clearfield Creek, Pennsylvania.

The barrier ridge of the Appalachian Mountain chain extends from New England to Georgia , and Alabama . Some of the local names, such as the Alleghenies for parts of the chain are marked; others are labeled on other maps on this page. Through the Appalachians west of the Berkshires, there were just five openings allowing east to west animal-powered travel within the United States up until the 1930s, [ a ] giving emphasis as to the importance of the three interiors mountain passes like the Gaps of the Allegheny Ridge.
Location of Kittanning Gap after GNIS finding of 'Kittanning Gap, Pennsylvania' seen in USGS National Map viewer screenshot. The gap is located effectively in a western suburb of Altoona .
• The maps on this page also are showing the nearby PRR Horseshoe Curve which crosses watercourses cutting three other gaps . GNIS software shows the Gap with the indicated ' A' marker well below the mouth of Kittanning Run .
• The Kittanning Gap name likely signifies a 'choice way' of climbing the escarpment to wagons or mule trains on the way to the west side of the Allegheny Mountains and Kittanning, PA . Taking a right through the gap to climb up the escarpment was a bit easier than either steep narrow creek beds straight ahead. This was one alternative routing through the area along what the 19th century would call the Kittanning Path .
This 1827 map shows the political map, the main water courses, and their relation to the key barrier ridges as seen by a reputed cartographer preparing this official map in the early years of the Main Line of Public Works (1824). The Allegheny Ridge is prominently shown in the map center-left, the gaps of the Allegheny Front are located in the border area between Cambria County (uplands) and Huntingdon County (lowlands).
USGS - Appalachians Mountain chain showing the lines of the barrier ridges in central, western, and northwestern Pennsylvania. Counting the Hudson Valley north of the Catskills in New York and the southern end of the chain on the Georgian plains , there are exactly three narrow areas where water gaps allowed climbing up to mountain passes allowing passage across the mountains was possible to animal pulled transport vehicles.
USGS combined topological and relief map mode view with search object "Kittanning Run". The Web software identifies the search item with short yellow point icon containing the ' A' (circled). This "official USGS confluence" is several miles from the official USGS Kittanning Gap ; the dark trace forming a hairpin turn directly below the marker is the Pennsylvania Railroad's famous Horseshoe Curve .
A closer look at the Appalachians and regional subordinate mountain ranges across New York State and New England .
USGS - Appalachians Mountain chain geomorphological classification zones in the Eastern United States.
This profile of the Allegheny Portage Railroad crossing the Allegheny Front gives valuable perspective at how the escarpment of the front and steepness of the gaps of the Allegheny created the final barrier range preventing easy settlement of the colonial and post-revolutionary-war west (today's Mid-west). It also illustrates the upland nature of the western side of the Front, the Allegheny Plateau but less clearly demonstrates the general barrier range nature of the other ridgelines of the Ridge-and-Valley Appalachians .