Bull Run Mountains facts for kids

The Bull Run Mountains are a mountain range in northern Virginia, United States. They are part of the larger Blue Ridge Mountains. These mountains are about 20 miles (32 km) east of the main Blue Ridge chain. They stand across the Loudoun Valley.

The Bull Run Mountains, along with Catoctin Mountain in Virginia and Maryland, form the eastern edge of the Blue Ridge.

This mountain range is home to the Virginia Outdoors Foundation's Preserve at Bull Run Mountains. This special area is a state-designated Natural Area Preserve. It's used for science and education. The Preserve has over seven miles of trails. These trails are open to the public year-round. You can visit on Fridays, Saturdays, and Sundays.

Several communities are also located within the mountain range. One of these is the Bull Run Mountain Estates.

Important roads and a railroad pass through the mountains. These include Interstate 66, the John Marshall Highway (Virginia Route 55), and the Manassas Gap Railroad. They all go through a spot called Thoroughfare Gap.

Exploring the Bull Run Mountains: Where Are They?

The Bull Run Mountains stretch for about 15 miles (24 km). They run from southwest to northeast. You can find them starting near Aldie in Loudoun County. They continue through western Prince William County. The range ends near New Baltimore in Fauquier County.

In the northern part, from Aldie to the start of Bull Run Creek, the mountains are entirely in Loudoun County. They form the eastern border of the southern Loudoun Valley. South of Bull Run Creek, the mountains create the western border of Prince William County with Fauquier County. This means the eastern slopes are in Prince William. The western slopes are in Fauquier.

How the Mountains Are Shaped

The Bull Run Mountains have three ridges that are close together. They also have several smaller "spurs" or branches. These ridges come together in the middle of the range.

The northern part of the mountains has just one ridge. This ridge gradually fades out towards the center. Then, two ridges to the west become more noticeable. In the southern part, the middle ridge also disappears. Only the westernmost ridge makes up the range there. The southern part of the Bull Run Mountains, south of Thoroughfare Gap, is sometimes called the Pond Mountains. The Broken Hills cross the range south of I-66 in this southern section.

Mountain Building: The Geology of Bull Run

The Bull Run Mountains share their geological story with Catoctin Mountain. They are made mostly of a type of rock called Catoctin greenstone. This greenstone has white quartz mixed in. It also contains very old Precambrian basalt rocks. These basalt rocks were changed by heat and pressure over millions of years.

The lower ridges on the eastern side of the mountains also have younger Jurassic basalt rocks. All these rocks were moved westward to where they are now. They were pushed up during a huge mountain-building event called the Alleghenian Orogeny.

A Glimpse into History: The Civil War Battle

A battle from the American Civil War took place on these mountains. It was called the Battle of Thoroughfare Gap. This battle happened right before the Second Battle of Manassas.

High Points and Passes: Peaks and Gaps

Here are some of the important peaks (high points) and gaps (passes) in the Bull Run Mountains, listed from north to south:

Notable Peaks

• Aldie Mountain [700 feet (210 m)]
• Long Hill Mountain [740 feet (230 m)]
• Bull Run Ridge [1,240 feet (380 m)]
• High Acre Ridge [1,320 feet (400 m)]
• Griffen Mountain [950 feet (290 m)]
• Fishback Ridge [880 feet (270 m)]
• Signal Mountain [1,369 feet (417 m)]
• High Point Mountain [1,311 feet (400 m)]
• Bisquit Mountain [850 feet (260 m)]
• Pond Mountain [840 feet (260 m)]

Important Gaps

• Buchannon Gap [587 feet (179 m)]
• Cold Spring Gap [702 feet (214 m)]
• Hopewell Gap [860 feet (260 m)]
• Thoroughfare Gap [423 feet (129 m)]