Rocks 200
Potomac River, at Harper's Ferry 246

The whole of the county east of the Catoctin Mountain varies from 200
to 350 feet. The eastern base of the Blue Ridge has an elevation of
about 730 feet, and the highest peak of that range in Loudoun rises
1,600 feet above tide-water.

The Short Hills have an approximate altitude of 1,000 feet, while that
of the Catoctin Mountain varies from 300 to 700 feet. The valley
between the Blue Ridge and Catoctin Mountains varies from 350 to 730
feet in elevation.

From many vantage points along the Blue Ridge may be obtained
magnificent views of both the Loudoun and Shenandoah valleys. The eye
travels entirely across the fertile expanse of the latter to where, in
the far distance, the Alleghany and North Mountains rear their wooded
crests. A few of the summits offer even more extensive prospects. From
some nearly all of Loudoun, with a considerable area of Fairfax and
Fauquier, is in full view. Other more distant areas within visionary
range are portions of Prince William, Rappahannock, and Culpeper
counties, in Virginia, Frederick and Montgomery counties, in Maryland,
and even some of Prince George County, east of Washington City.
Westward, the view embraces Shenandoah, Frederick, Clarke and Warren
counties, in Virginia, Berkeley and Jefferson counties, in West
Virginia, Washington County, in Maryland, and some of the mountain
summits of Pennsylvania.

DRAINAGE.

The drainage of Loudoun can be divided into two provinces. One is the
Potomac province, which is drained by a system of small tributaries of
that stream. Its elevations are quite uniform and are referable to
that master stream, whose grade is largely determined by its great
basin beyond the "Catoctin belt." The second province is the region
drained by smaller streams, chief of which is Goose Creek. In this
province the drainage lines head entirely within the "Catoctin belt,"
and the elevations are variable according to the constitution of the
rocks in the belt itself.

The tributaries by which the drainage of the two provinces is effected
are Catoctin Creek, North Fork Catoctin Creek, South Fork Catoctin
Creek, Little River, North Fork Goose Creek, Beaver-dam Creek, Piney
Run, Jeffries Branch, Cromwells Run, Hungry Run, Bull Run, Sycoline
Creek, Tuscarora Creek, Horse Pen Run, Broad Run, Sugarland Run, Elk
Lick, Limestone Branch, and as many lesser streams.

The general slope of the county b