The highest elevation summit, Mount Everest, shown with a climber at the summit wearing an oxygen mask. The summit is 8.8 km up (29k ft), while the cruising altitude of airliners is roughly 10 km (33k feet). However, airliners are pressurized.
View from the summit of Switzerland's highest, Monte Rosa
The term "summit" is generally only used for a mountain peak with some significant amount of topographic prominence (height above the lowest point en route to the nearest higher peak) or topographic isolation (distance from the nearest point of higher elevation); for example, a boulder next to the main summit of a mountain is not considered a summit. Summits near a higher peak, with some prominence or isolation, but not reaching a certain cutoff value for these quantities, are often considered subsummits (or subpeaks) of the higher peak, and are considered as part of the same mountain. The UIAA definition is that a summit is independent if it has a prominence of 30 metres (98 ft) or more; it is a mountain if it has a prominence of at least 300 metres (980 ft). This can be summarised as follows:
< 30 m
Independent peak or summit
30 m or more
300 m or more
A pyramidal peak is an exaggerated form produced by ice erosion of a mountain top. Summit may also refer to the highest point along a line, trail, or route. In many parts of the western United States, the term refers to the highest point along a road, highway, or railroad. For example, the highest point along Interstate 80 in California is referred to as Donner Summit (not to be confused with Donner Pass, which is located just to the south.)