Mountain
Heights of mountains are typically measured above sea level. Using this metric, Mount Everest is the highest mountain on Earth, at . There are at least 100 mountains with heights of over above sea level, all of which are located in central and southern Asia. The highest mountains above sea level are generally not the highest above the surrounding terrain. There is no precise definition of surrounding base, but Denali, Mount Kilimanjaro and Nanga Parbat are possible candidates for the tallest mountain on land by this measure. The bases of mountain islands are below sea level, and given this consideration Mauna Kea ( above sea level) is the world's tallest mountain and volcano, rising about from the Pacific Ocean floor.
Allegheny Mountains
The highest ridges of the Alleghenies are just west of the Front, which has an east/west elevational change of up to . Absolute elevations of the Allegheny Highlands reach nearly , with the highest elevations in the southern part of the range. The highest point in the Allegheny Mountains is Spruce Knob (4,863 ft/1,482 m), on Spruce Mountain in West Virginia. Other notable Allegheny highpoints include Thorny Flat on Cheat Mountain (4,848 ft/1478 m), Bald Knob on Back Allegheny Mountain (4,842 ft/1476 m), and Mount Porte Crayon (4,770 ft/1,454 m), all in West Virginia; Dans Mountain (2,898 ft/883m) in Maryland, Backbone Mountain (3360 ft/1024 m), the highest point in Maryland; Mount Davis (3,213 ft/979 m), the highest point in Pennsylvania, and the second highest, Blue Knob (3,146 ft/959 m).