Elevation gain/loss estimate methodology

Elevation gain/loss estimations provided by Steve Shuman.

It's useful to know how much a trail goes up and down. Hikers thinking about hiking part of a trail, whether it's rugged or easy terrain they are looking for, can use information about how much a segment rises and falls to make their decision. Thru-hikers can use the information to help determine how long it's likely to take them to get to their next resupply point. And all hikers can benefit from this knowledge toward the end of the day when deciding whether to push on to that next shelter or road crossing.

But what's the best way to figure out how much elevation gain and loss to expect? Some find the elevation profiles on AT maps to be handy, but sometimes these profiles have their drawbacks. It's not uncommon for hikers to be surprised by the ruggedness of a section of trail that looked easier on the elevation profile. And different maps often use different profile scales, some exaggerating rise and fall more than others.

Others might use electronic databases like the ATC's centerline data available for download. But after seeing this centerline data, and data from commercial map companies as well, plotted graphically onto satellite photos or topographic maps (using google earth, for one), it's easy to see that none of them have a data point at every single spot on the trail where rising ground changes to falling ground, and vice-versa, which is what you would need to accurately compute elevation gain and loss using these electronic resources.

But a much more low-tech solution is available. One can look at the USGS 7.5 minute topographic maps for the entire trail and count the contour lines the trail crosses, going both up and down. All one needs are all the ATC maps (to spot any trail changes that have occured since the various USGS maps were published), USGS maps, and a lot of time and tolerance for tedium.

Thanks to Steve Shuman for both coming up with this innovative approach and putting in the effort to find the elevation gain and loss for each point within the Distance Calculator. Steve would like to offer a couple of disclainers for all those who utilize this data.

First, elevation gain and loss per mile is not the only determiner of how difficult a stretch of trail is. Many who've hiked both the AT and Pacific Crest Trail will tell you that a day with 4000 feet of elevation gain on the PCT often feels much easier than a day on the AT climbing the same amount. The quality of the treadway has a lot to do with this. But, still, the amount of climbing and falling is the single most important factor contributing to ruggedness in most circumstances.

Second, this data is only as current as the ATC maps, and those vary in publication date from very recent to as old as 1998. So any trail reroutes since the map publication will have an effect on some small sections. Also, due to the extensive amount of manual labor involved, these elevation values may not be updated immediately even after the ATC maps are updated.

An earlier description of this work done by Steve Shuman can be found here.