Elevation is the handle for the vertical distance a point is above sea level. Never mind the sea is anything except level and it's surface is in constant motion; always either rising or falling.
Spend a little time looking at standard highway maps and one is bound to notice there are occasion's when elevation of a particular location is noted thereon: Usually in mountain country, associated with a mountain pass through which a highway is routed. Prominent mountain peaks locations and elevations are also indicated on most highway maps for some unknown reason, except perhaps to fill in some of the blank areas on those highway maps where there is a noticeable lack of any roads, let alone a modern highway. For years I've wondered why the map makers put such a useless bit of information on almost all U.S. highway maps.
It makes sense that someone might want to know just how high a highway is; maybe they get dizzy when they get too high, or maybe their auto doesn't have the power to climb over a certain height. Maybe. It also makes sense that an airplane pilot would need to know how high he has to fly to clear a mountain; and, if the plane can't gain the required altitude to fly over the mountains then perhaps between them, or even around them if necessary. On the eastern side of the Rocky Mountains, the roads generally go a great distance to do just that: go around rather than through the mountain ranges. But in those areas the pass elevations are not indicated while any unusually high peaks are still included. Besides, after checking with a few aircraft pilots I've learned that while maps are important tools for a pilot, none of them use highway maps. No, mountain peak elevations are not there for aircraft pilots.
This year I finally found a use for that trivial bit of mostly useless information when a new acquaintance who had moved here from Colorado claimed the mountains in Colorado were bigger, higher, than the mountains in Oregon. Since we were traveling by car when that statement was made, There was no problem checking the facts and proving the claim to be unfounded.
As my friend drove, I inspected the maps on hand, and found Mount Shasta in Northern California is higher than any in Colorado. Mounts Hood, Jefferson and Washington are every bit Colorado's peaks peers. Mount Mozuma, Crater Lake, is nearly as high as the average peaks marked on the Colorado map, and it blew it's top clean away in the manner of Mount Saint Helens more recent event.
After giving that some thought, I decided that Oregon's mountains must be taller than those in Colorado. In Colorado, the mountains begin to rise from an elevation measured in thousands of feet; while in Oregon, the mountains begin to rise from an elevation measured in mere hundreds of feet. My home, in the Santiam Canyon, is only 820 feet above sea level. An elevation which one would have to dig a very deep hole to reach in Colorado.
I ask again: How High, is High?