Peakbagger.com Help and GlossaryClean ProminenceProminence is the vertical distance a given summit rises above the lowest col connecting it to a higher summit. To calculate it, you must know the elevation of a summit and the elevation of its key col. A problem arises when one or both of these elevations are not known precisely. Most commonly, col elevations are not given on topographic maps, so all that is known is a range based on a contour interval. Many summits also are represented by just a closed contour and no exact elevation. There are three ways to deal with this uncertainly when calculating prominence:
This site uses clean prominence for ranking peaks and setting cut-off values, mainly because it is impossible to overstate a peak elevation or prominence value using that method. Values may be higher, but no peak will ever get extra undeserved elevation. This seems like the safest method, and is commonly used by current prominence researchers. ColCol is the standard term used on this site to refer to the lowest point on the ridge between two summits. There are many synonyms: Pass, Gap, Saddle, Notch, or Cut; Joch in German, Colle in Italian, etc. See Key Col for the specialized meaning of that term. County High Points by Andy MartinIn compiling the lists for this site, an extremely valuable reference work was a book called, simply, County High Points. This spiral-bound "bible" lists the highest points of all 3,141 counties in the United States, plus the most prominent peaks in virtually all mountainous areas of the country. It also contains unexpected goodies such as a list of Mexican State high points and U.S. National Park high points, plus a nice explanation of the prominence concept. Ordering Summary Information for the County High Points book by Andy Martin:To order send check or money order for $10 to Andy Martin, 3030 N. Sarsaparilla Pl., Tucson AZ 85749-9237 Details:This 128 page soft cover comb bound 8.5" x 11" book lists the 3140+ county high points for all 50 states. Lists are also given for high prominence peaks, National Park HPs, and Mexican state HPs. The introduction goes into some detail on how the lists were prepared. The information in the lists can be used to look up high point area maps on www.topozone.com. For example, the Pima county Arizona high point is listed: Lists are also available for the 50 "finest" peaks in 14 western states - AZ, CA, NM, NV, CO, UT, TX, OR, WA, ID, MT, WY, HI and AK. Finest lists for the NE and SE sections of the US are also included. To order send a check for $8.00 plus $2.00 shipping & handling ($10 total) to: Prices are current for 2004.
Shipping will be by USPS book rate, which will take a week or more. If not satisfied for any reason, book can be returned for a full refund.
Most of the county high point and prominence lists on the Peakbagger.com site were largely developed by myself over a long period of years, but Andy Martin's County High Points book was used as an indispendible reference as I compiled my lists. Here is a summary of some of the differences between the lists on this site and in the book:
So, if you are serious about county high pointing, especially in non-mountainous areas, you should definitely purchase the book and not rely on the information on Peakbagger.com. On this site you can pull up lists for selected states, and link to a topo map of the general area, but there may be other areas not listed that are higher. See also County Highpointer Site. This web site gives credit to the County High Points book on all peak list pages where it was used as a reference. The specific credit information from the book is listed at the bottom of each of these lists. Every peak on a high point list is the highest point of something. Every piece of geography on earth (natural or human-defined) theoretically has a high point; continents, countries, states, counties, parks, islands, mountain ranges, and even backyards all have area extent and some kind of topography. The lists in this section can be thought of as having two parameters: the kind of geography giving us the high points (e.g. countries, states); and the universe that holds these geographies (e.g. the world, the U.S.A.). Note that it is very common for two or three geographies to share the same exact summit as a high point, and in these cases the summit is listed two or three times, once for each geography. Isolation for any given summit is defined as the distance from that summit to the nearest higher land. This distance is usually given in miles or kilometers, and represents the radius of the area where the peak is the highest point. The concept is easy to grasp with some examples. The isolation for Mt. Everest is undefined or infinite, since there is no nearest higher land. But every other summit can be assigned an isolation value. After Mt. Everest, the peak with the
highest isolation is Aconcagua, with a value of 10,257 miles to the nearest higher peak, in Afghanistan. For K2, the isolation is 818 miles, the distance to Mt. Everest. The nearest higher peak by straight line distance to a given peak is called the Nearest Higher Neighbor or NHN.
There are a few quirks to using this method as a measuring tool for mountains. Low hills that are highpoints of isolated mid-oceanic islands will often have abnormally high isolation values, since there is no land at all (higher or not) nearby. The highest peak on Tristan da Cunha in the mid-Atlantic is not on many lists of the world’s most significant summits, but it ranks about #16 in the world in isolation. For this reason, in some isolation lists on this site small island high points are excluded from rankings. Compared to prominence, isolation rewards summits that may be very low but that dominate a large area. For example, Eagle Mountain in Minnesota and Magazine Mountain in Arkansas both have isolation values that make them seem much more impressive than prominence ever would. In theory, the nearest higher land for a peak will almost always be some point on a slope or ridge, but in practice the calculation is done using the nearest higher summit instead. The difference is usually not much. However, the isolation values on this site are calculated to the nearest higher peak in the master database, and often the NHN will be a very minor summit that is not in the database, so the isolation numbers can be substantially higher than they really are for many peaks. Also, if there are two very close summits with the same elevation, they can both be very isolated, since the rule used is distance to a higher peak, not a higher or equal elevation peak. The key col (saddle, pass, gap) is an important concept related to Prominence.
Every peak that is not a landmass/island high point is connected to a higher
peak by ridges and has exactly one key col, which is the lowest one
connecting it to a higher peak. The mathematical correspondence between (non
island/landmass high point) peaks and key cols is 1:1, so any given pass is
the key col for just one peak. A minor sub-peak's key col is usually very close to the sub-peak, being the
low point on the ridge connecting it to the nearby higher peak. Major summits,
though, will often have a key col far away. For example, to find the key
col for Mount McKinley (Denali), you must follow ridges south all the way to
the Andes, the closest higher peaks. The lowest point on this three thousand
mile ridge walk is in Nicaragua, and that is where McKinley's key col lies.
Another famous example is the key col for Mount Mitchell, highest point in
the Appalachians--you must follow ridges across the Midwest to the Rockies to
find the nearest higher peaks, and the low point is in Chicago, Mitchell's key
col. When calculating isolation, one must measure distance from a given summit to the closest higher land, in practice the closest nearest summit. This closest higher summit is called the Nearest Higher Neighbor, or NHN. Every peak on earth except Mount Everest has a NHN. Great circle, as-the-crow-flies distance is always used to find the NHN for a peak. Often the NHN for a peak will be a very minor sub-peak or ridge spur, and is not in the Peakbagger.com mountain database, meaning that many isolation values listed on this site are too high. Every peak that is not a landmass/island high point has a key col and a prominence value. The Nearest Topographic Higher Peak (NTHP) is defined as the closest higher peak to a given
summit, following ridgelines past the key col. For a minor sub-peak, the NTHP will generally be the main peak that it is subsidiary to. For example, from the South Peak of Mount Elbert you follow a ridge down to the key col, and then up to Mount Elbert itself, the HTHP for
the South Peak. For major, prominent summits, the NTHP is often far away and is sometimes a minor or surprising peak. For example, for Mount Mitchell, highest of the Appalachians, you must follow ridges across the Midwest, past its key
col in Chicago, and the NTHP will be the first peak rising above Mitchell's 6684-foot elevation as the divide nears the continental divide in Montana (appropriately named Divide Mountain).
Often the ridge past a peak's key col will split, with each fork leading to a higher peak. In this case, the NTHP is the one closest to the given peak, using distance along the ridgelines. The HTHP is not to be confused with the "Prominence Parent", which is the
generally defined as the peak that will be the high point of a theoretical
island if the ocean were to rise to just below the key col for a given peak.
So, for example, for Mount McKinley (Denali), the HTHP is Chimborazo, the first
higher peak you encounter as you move south along the continental divide. The
Prominence Parent would be Aconcagua, since that would be the high point of an
island with narrow isthmus at the key col. The Peakbagger.com database does
not store Prominence Parent information. Many peaks, and most cols/saddles, do not have exact spot elevations on topographic maps. Therefore, the elevations for these features can only be expressed as a range. When calculating a prominence value for a peak (summit elevation minus key col elevation), the value is called "optimistic" when the highest possible summit elevation and lowest possible key col elevation are used. This number is the maximum possible prominence value for a peak, and will almost always be an overstatement of the true value. This site generally uses Clean Prominence for prominence-based lists, not optimistic prominence The Peakbagger.com Database (PBC Database) is a large, complex computer database that stores information on over 12,000 mountain peaks, 2000 mountain ranges, and other associated information. However, it is not by any means complete, since there are theoretically millions of peaks that are simply not in it. This means that many of the automatically-generated web pages on this site contain errors of omission. In particular, isolation distances that are calculated for peaks will be greatly overstated if the true nearest higher peak is not in the database. Also, the simple lists of the ten highest peaks in a given mountain range will often have less than ten peaks, or, very often, list the wrong ten peaks. Of course, the goal of the PBC Database is to eventually have records for most of the world's high, important, prominent, isolated, or otherwise noteworthy peaks. I will freely admit that right now the database is much more complete in the United States than anywhere else, and more complete in Canada and Europe than in Africa and Asia. In order to be included in the PBC Database, a peak must have a name, an elevation (feet or meters), and an accurate latitude/longitude (WGS84 decimal degrees). If you have this information for a peak you would like to see added, you can e-mail information to the address listed on the Contact Page. ProminenceProminence is defined as the vertical distance a given summit rises above the lowest col connecting it to a higher summit. Or, put another way, it is the elevation difference between the summit of a peak and the lowest contour that contains the given peak and no higher peaks. Imagine the ocean rising to the exact point where a certain peak is the highest point on its very own island. At that point, the prominence is the elevation of the peak above the risen ocean. That all sounds confusing, yet prominence is actually a fairly intuitive and commonly used concept. It goes by other names ("shoulder drop", "vertical rise", and other terms) and is central to a great deal of mountain peak listing activity. The best way to visualize it is to imagine that you are on a major summit and you start hiking down a ridge. After descending for 1000 feet, you start climbing again and gain 200 vertical feet to gain a sub-peak along the ridge. This sub-peak has a prominence of 200 feet, since that is how far it rises above the col connecting it to the major summit. See the glossary entries for key col, clean prominence and optimistic prominence for more about prominence. Also related is the idea of a nearest topographic higher peak. The traditional use of prominence is to use it as a way to determine which peaks belong on a threshold list. If, for example, you wanted to see a list of the peaks above 14,000 feet in Colorado, you could in theory count every large boulder on every ridge as a peak and generate a list with thousands of summits. However, if you say that a peak must rise above 14,000 feet and have a prominence of 200 feet, then you have a much more manageable and appealing list. Prominence provides an essential criteria for any threshold list, and a lively debate about the right value to use surrounds many of the more famous threshold lists. Calculating prominence for minor summits close to major ones is easy, since the key col is close. Recently, though, dedicated map-readers have started finding the prominence for major summits, where the key col is often very far away. This allows for lists to created that rank peaks by prominence value, not by the traditional elevation. On these lists, a low elevation peak with greater prominence ranks higher than many well-known higher peaks. These lists provide a new and interesting way to look at peaks in an area. Prominence is not a perfect measure of a mountain. Volcanoes and high points of desert fault-block ranges tend to have very high prominence values, and summits in major mountain ranges outside of the range high point tend to have lower values than one might expect. Many feel that prominence-based lists yield a more impressive line-up of summits than traditional threshold lists, but intangibles such as ruggedness, beauty, and personable inspiration are still not factored in. Threshold ListsA threshold list shows all peaks above a certain elevation threshold in a certain area. The geographical area is usually a well-defined political unit or mountain range, and the elevation threshold is frequently a round number (e.g. 8000 meters, 14,000 feet). Sometimes these lists have a fixed number of peaks, such as the 100 highest--this is really just a threshold list with a very specific, non-round number elevation threshold. All threshold lists also require another parameter, which is a way to determine which peaks should get ranked or not. Theoretically, every boulder on a ridge above the threshold could be a peak on the list, so these lists often use prominence or isolation as a qualifying factor. On this site, all threshold lists use an associated prominence value, and peaks with prominence below it are not given a numerical ranking. These sub-peaks are shown in the list for reference, but do not have a rank. To move the unranked sub-peaks to the bottom of the list, click on the rank column to sort the list by the rank number. WinProm ProgramCalculating the prominence of a peak can be very tedious work, since the key col is often very far away from a high-prominence peak, and it can take hours to pore over maps, following obscure divide lines to find the low point of a connecting ridge. A big help was provided by mathematician Edward Earl, who wrote a computer program called WinProm that uses USGS Digital Elevation Model (DEM) databases to automatically calculate peaks, ridges, and key cols. DEMs are large matrices of elevations that cover an area at various resolutions, for example, every 30 seconds (about 0.3 to 0.6 mile). This data is not as accurate as a topographic map, but the program saves time by identifying areas where high peaks are, and areas where the key col is likely to be found. The program is very complex and has many enhancements, such as algorithms that try to match DEM maxima to known peak locations. Many of the prominence figures on this site for summits with high (greater than 2000 feet) prominence had their genesis in the output from the WinProm program.
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