History and Comprehensive Description of Loudoun County, Virginia | Page 5

below the Cool
Spring Gap. The line then extends to the summit of the mountain,
where the counties of Fauquier and Prince William corner. From the
summit of this mountain, a direct line to a point[4] on the Blue Ridge,
at Ashby's Gap, marks the boundary between Loudoun and Fauquier
counties. A devious line, which follows in part the crests of the Blue
Ridge until reaching the Potomac below Harpers Ferry, separates
Loudoun from Clarke County, Virginia, and Jefferson County, West
Virginia, on her western border. The Potomac then becomes the
dividing line between Loudoun County, and Frederick and
Montgomery counties, Maryland; "and that State, claiming the whole
of the river, exercises jurisdiction over the islands as well as the river."
[Footnote 3: "What is called Lowe's Island, at the mouth of Sugarland
Run, was formerly an island, and made so by that run separating and
part of it passing into the river by the present channel, while a part of it
entered the river by what is now called the old channel. This old
channel is now partially filled up, and only receives the waters of
Sugarland Run in times of freshets. Occasionally when there is high
water in the river the waters pass up the present channel of the run to
the old channel, and then follow that to the river again. This old
channel enters the river immediately west of the primordial range of
rocks, that impinge so closely upon the river from here to Georgetown,

forming as they do that series of falls known as Seneca Falls, the Great,
and the Little Falls, making altogether a fall of 188 feet in less than 20
miles."--Memoir of Loudoun.]
[Footnote 4: Designated in an old record as a "double-bodied poplar
tree standing in or near the middle of the thoroughfare of Ashby's Gap
on the top of the Blue Ridge." It succumbed to the ravages of time and
fire while this work was in course of preparation.]
This completes an outline of 109 miles, viz: 19 miles in company with
Fairfax, 10 with Prince William, 17 with Fauquier, 26 with Clarke and
Jefferson, and 37 miles along the Potomac.
TOPOGRAPHY.
Loudoun County is preeminently a diversified region; its surface
bearing many marked peculiarities, many grand distinctive features.
The broken ranges of hills and mountains, abounding in Piedmont
Virginia, here present themselves in softly rounded outline, gradually
sinking down into the plains, giving great diversity and picturesqueness
to the landscape. They are remarkable for their parallelism, regularity,
rectilineal direction and evenness of outline, and constitute what is by
far the most conspicuous feature in the topography of Loudoun. Neither
snow-capped nor barren, they are clothed with vegetation from base to
summit and afford fine range and pasturage for sheep and cattle.
The main valleys are longitudinal and those running transversely few
and comparatively unimportant.
The far-famed Loudoun valley, reposing peacefully between the Blue
Ridge and Catoctin mountains, presents all the many varied
topographic aspects peculiar to a territory abounding in foothills.
The Blue Ridge, the southeasternmost range of the Alleghanies or
Appalachian System presents here that uniformity and general
appearance which characterizes it throughout the State, having gaps or
depressions every eight or ten miles, through which the public roads
pass. The most important of these are the Potomac Gap at 500 feet and

Snickers and Ashby's Gap, both at 1,100 feet. The altitude of this range
in Loudoun varies from 1,000 to 1,600 feet above tide-water, and from
300 to 900 feet above the adjacent country. It falls from 1,100 to 1,000
feet in 4 miles south of the river, and then, rising sharply to 1,600 feet,
continues at the higher series of elevations. The Blue Ridge borders the
county on the west, its course being about south southwest, or nearly
parallel with the Atlantic Coast-line, and divides Loudoun from Clarke
County, Virginia, and Jefferson County, West Virginia, the line
running along the summit.
Of nearly equal height and similar features are the Short Hills, another
range commencing at the Potomac River about four miles below
Harpers Ferry and extending parallel to the Blue Ridge, at a distance of
nearly four miles from summit to summit, for about twelve miles into
the County, where it is broken by a branch of Catoctin Creek. Beyond
this stream it immediately rises again and extends about three miles
further, at which point it abruptly terminates.
A third range, called "Catoctin Mountain," has its inception in
Pennsylvania, traverses Maryland, is interrupted by the Potomac,
reappears in Virginia at the river margin, opposite Point of Rocks, and
extends through Loudoun County for a distance of twenty or more
miles, when it is again interrupted.
Elevations on Catoctin Mountain progressively diminish southward
from the Potomac River to Aldie, although the rocks remain the same,
and the