Shenandoah Mountain is a mountain ridge

Ridge

A ridge is a geological feature consisting of a chain of mountains or hills that form a continuous elevated crest for some distance. Ridges are usually termed hills or mountains as well, depending on size. There are several main types of ridges:...

 approximately 73 miles (117.5 km) long in Virginia

Virginia

The Commonwealth of Virginia , is a U.S. state on the Atlantic Coast of the Southern United States. Virginia is nicknamed the "Old Dominion" and sometimes the "Mother of Presidents" after the eight U.S. presidents born there...

 and West Virginia

West Virginia

West Virginia is a state in the Appalachian and Southeastern regions of the United States, bordered by Virginia to the southeast, Kentucky to the southwest, Ohio to the northwest, Pennsylvania to the northeast and Maryland to the east...

. The steep, narrow, sandstone-capped ridge extends from northern Bath County, Virginia

Bath County, Virginia

As of the census of 2000, there were 5,048 people, 2,053 households, and 1,451 families residing in the county. The population density was 10 people per square mile . There were 2,896 housing units at an average density of 5 per square mile...

 to southern Hardy County, West Virginia

Hardy County, West Virginia

As of the census of 2000, there were 12,669 people, 5,204 households, and 3,564 families residing in the county. The population density was 22 people per square mile . There were 7,115 housing units at an average density of 12 per square mile...

. Along the way, its crest defines the borders between Highland

Highland County, Virginia

As of the census of 2000, there were 2,536 people, 1,131 households, and 764 families residing in the county. The population density was 6 people per square mile . There were 1,822 housing units at an average density of 4 per square mile...

 and Augusta

Augusta County, Virginia

As of the census of 2000, there were 65,615 people, 24,818 households, and 18,911 families residing in the county. The population density was 68 people per square mile . There were 26,738 housing units at an average density of 28 per square mile...

 counties, Virginia, and between Pendleton County, West Virginia

Pendleton County, West Virginia

As of the census of 2000, there were 8,196 people, 3,350 households, and 2,355 families residing in the county. The population density was 12 people per square mile . There were 5,102 housing units at an average density of 7 per square mile...

, and Rockingham County, Virginia

Rockingham County, Virginia

As of the census of 2000, there were 67,725 people, 25,355 households, and 18,889 families residing in the county. The population density was 80 people per square mile . There were 27,328 housing units at an average density of 32 per square mile...

.

Located in the Ridge and Valley

Ridge-and-valley Appalachians

The Ridge-and-Valley Appalachians, also called the Ridge and Valley Province or the Valley and Ridge Appalachians, are a physiographic province of the larger Appalachian division and are also a belt within the Appalachian Mountains extending from southeastern New York through northwestern New...

 physiographic province

Physiographic province

A physiographic province is a geographic region with a specific geomorphology and often specific subsurface rock type or structural elements.A continent may be subdivided into various physiographic provinces, each having a specific character, relief, and environment which contributes to its...

 of the Appalachian Mountains

Appalachian Mountains

The Appalachian Mountains #Whether the stressed vowel is or ,#Whether the "ch" is pronounced as a fricative or an affricate , and#Whether the final vowel is the monophthong or the diphthong .), often called the Appalachians, are a system of mountains in eastern North America. The Appalachians...

, Shenandoah Mountain forms part of the western margin of the Shenandoah Valley

Shenandoah Valley

The Shenandoah Valley is both a geographic valley and cultural region of western Virginia and West Virginia in the United States. The valley is bounded to the east by the Blue Ridge Mountains, to the west by the eastern front of the Ridge-and-Valley Appalachians , to the north by the Potomac River...

, and is part of the easternmost Allegheny Mountains

Allegheny Mountains

The Allegheny Mountain Range , also spelled Alleghany, Allegany and, informally, the Alleghenies, is part of the vast Appalachian Mountain Range of the eastern United States and Canada...

. It lies almost entirely within the George Washington National Forest. U.S. Route 33

U.S. Route 33

U.S. Route 33 is a United States federal highway that runs northwest-southeast for 709 miles from northern Indiana to Richmond, Virginia, passing through Ohio and West Virginia en route. Although most odd-numbered U.S...

 crosses the mountain between Franklin, West Virginia

Franklin, West Virginia

Franklin is a town in Pendleton County, West Virginia, United States. The population was 797 at the 2000 census. It is the county seat of Pendleton County...

, and Harrisonburg, Virginia

Harrisonburg, Virginia

Harrisonburg is an independent city in the Shenandoah Valley region of Virginia in the United States. Its population as of 2010 is 48,914, and at the 2000 census, 40,468. Harrisonburg is the county seat of Rockingham County and the core city of the Harrisonburg, Virginia Metropolitan Statistical...

.

Shenandoah Mountain's highest peaks are Reddish Knob

Reddish Knob

Reddish Knob of Shenandoah Mountain is one of the highest points in Virginia, rising . No other peak rises higher to the northeast before New York's Catskills...

(Virginia/West Virginia; 4397’/1340 m http://www.peakbagger.com/peak.aspx?pid=7590), Flagpole Knob (Virginia; 4383’/1336 m http://www.peakbagger.com/peak.aspx?pid=7589), and Bald Knob (Virginia; 3680’/1122 m http://www.peakbagger.com/peak.aspx?pid=18414).