Tygart Valley River
 The Tygart Valley River — also known as the Tygart River — is a principal tributary of the Monongahela River approximately 135 miles (217 km) long in east-central West Virginia USA. Via the Monongahela and Ohio rivers it is part of the watershed of the Mississippi River draining an area of 1329 square miles (3440 km2) in the Allegheny Mountains and the unglaciated portion of the Allegheny Plateau.