elevated and hilly region, deeply indented by the myriad streams that
rise in its bosom.

On reaching the Leesburg and Snicker's Gap Turnpike road, a distance
of twelve miles, it expands to three miles in width and continues much
the same until broken by Goose Creek and its tributary, the North
Fork, when it gradually loses itself in the hills of Goose Creek and
Little River, before reaching the Ashby's Gap Turnpike.

The Catoctin range throughout Loudoun pursues a course parallel to the
Blue Ridge, the two forming an intermediate valley or baselevel
plain, ranging in width from 8 to 12 miles, and in altitude from 350
to 730 feet above sea level. Allusion to the physiography of this
valley--so called only by reason of its relation to the mountains on
either side--has been made elsewhere in this department.

Immediately south of Aldie, on Little River, near the point of
interruption of Catoctin Mountain, another range commences and extends
into Fauquier County. It is known as "Bull Run Mountain," but might
rightly be considered an indirect continuation of the elevation of the
Catoctin, its course and some of its features corresponding very
nearly with that mountain save only that it is higher than any of the
ranges of the latter, excepting the western.

East of the Catoctin the tumultuous continuity of mountains subsides
into gentle undulations, an almost unbroken succession of sloping
elevations and depressions presenting an as yet unimpaired variety and
charm of landscape. However, on the extreme eastern edge of this
section, level stretches of considerable extent are a conspicuous
feature of the topography.