An elevation sign at 8,000 feet^{[convert: %s]}%s in the San Bernardino Mountains.

When talking about geography the elevation of a certain point is how high it is compared to some reference point. Very often, the reference point is mean sea level, the level of the ocean midway between high and low tide on an average day. Most land has a positive elevation, which means it is above sea level. A few desert places are below sea level, thus have negative elevation.