A gap is a geological formation that is a low point or opening between hills or mountains or in a ridge or mountain range.
Geomorphologically, a gap is most often carved by water erosion from a freshet, stream or a river.
[1] Gaps created by freshets are often, if not normally, devoid of water through much of the year, their streams being dependent upon the meltwaters of a snow pack.
Gaps sourced by small springs will generally have a small stream excepting perhaps during the most arid parts of the year.
Such cuttings may expose millennia of strata in the local rock column writing the geologic record.
A zoomed in view of the image below showing the Location of Kittanning Gap, one of the
gaps of the Allegheny
, along a tributary of the Kittanning Run.
• The USGS GNIS systems placement of the location of
Kittanning Gap
, is along a tributary of the
Kittanning Run
, not in the notch formed by the main stream. The black trace in this map forming a
hairpin turn
above the Lakes is the famous & historic
Horseshoe Curve
built by the
Pennsylvania Railroad
which crosses over four different
streams
sitting in the bottom end of
water gaps
in the view, and finishes its climb in a fifth, seen below in the next (zoomed out) map, just north of a sixth
Blair Gap
, where the historical
Allegheny Portage Railroad
climbed the Allegheny escarpment heading west.
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, PA
.
• The maps on this page also are showing the nearby
PRR
Horseshoe Curve
which crosses three other gaps and the confluence of
Kittanning Run
with .
• The Kittanning Gap gives
this '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
along the
Kittanning Path
. Taking a right through the gap to climb up the escarpment was a bit easier than either steep narrow creek beds straight ahead..
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). Note that this '
official
USGS
confluence
' is several miles from the official USGS Kittanning Gap.
• The dark trace forming a
hairpin turn
directly below that marker is the
Pennsylvania Railroad
's famous
Horseshoe Curve
.