Why Do Hiking Maps Lie?

Why Do Maps Lie?

Have you ever heard the expression, “maps lie?” It’s due to the fact that all maps, including topographic hiking maps, leave out information deemed irrelevant for their intended use. This is even true of the maps published by the US Geological Survey (USGS) which are considered the gold standard for maps in the United States.

Topographic Scale

Topographic maps are designed to provide a three-dimensional view of the world using contours lines to reflect changes in elevation. If the contour interval is very small, they capture a lot of detail. But if the contour interval is large, like 100′ or more, a lot of detail is lost. This isn’t a big deal if you’re hiking on a well-defined trail which avoids annoying obstacles like small cliffs and gullies, but if you’re traveling cross country, a large contour interval obscures small dips and bulges in the landscape that require a lot more energy to bypass or hike over.

Missing Trails

When it comes to hiking trail maps, many map makers don’t include other types of trails on their maps even though they intersect each other or are located nearby (see below). But if you’re bushwhacking, geocaching, hunting, fishing, surveying, or any number of other activities, this missing information is important to know about because it can make it easier to move around in the backcountry.

  • logging roads
  • fire roads
  • forest service roads
  • snowmobile trails
  • ATV trails
  • rail trails
  • mountain biking trails
  • ski trails

Other Missing Information

There are other types of information that are often missing or out of date on hiking trail maps and USGS topographical maps, that’s also very useful if you stray away from well-established trails.

  • Private property boundaries, which are important if you need prior permission to enter someone else’s property to camp, hunt, or fish there.
  • New trails, trail reroutes, and trail closures.
  • Bridges, especially footbridges that have been washed away by spring floods.
  • Major landform changes such as changed river watercourse flows, flash flood damage, and avalanche slides.
  • Large scale man-made changes like timber cuts or new roads.

Planning, planning, planning

The best way to overcome the missing information found on maps is to collect a lot of different maps when planning a route, including online or digital maps in apps.

  • Caltopo.com is an online planning tool that I use frequently to plan hikes and backpacking trips. It is free to use online and provides many different views (maps) of the same area, including historic USGS maps which are very useful for finding old trails and roads.
  • The Gaia Phone App also contains a lot of different maps, but is very focused on trail hiking as opposed to off-trail hiking.
  • The OnX Hunt App is the antidote to Gaia’s hiking trail focus and is designed more for off-trail hunting, scouting, and bushwhacking. It contains many more trail types including logging roads, snowmobile, and ATV trails. It also lists private property boundaries and owner names so you can get permission to cross private property.
  • Don’t forget to check the free maps distributed by the USFS, NPS, and BLM when looking for information about unpaved roads.
  • Local shops frequently carry maps of local ATV or snowmobile trails that are worth buying when you see them.
  • Also, be sure to seek out local sources such as online forums, Facebook groups, newsgroups, and trip reports to obtain up to date information.

More Frequently Asked Questions

About the author

Philip Werner has hiked and backpacked over 7500 miles in the United States and the UK and written over 2500 articles as the founder of SectionHiker.com, noted for its detailed gear reviews and educational content. A devotee of New Hampshire and Maine hiking and backpacking, Philip is the 36th person to hike all 650 of the hiking trails in the White Mountain Guide. He is also the author of Backpacking the White Mountain 4000 Footers, a free online guidebook of the best backpacking trips in the White Mountains in New Hampshire and Maine. In addition, Philip volunteers as a 4 season backpacking leader for the Appalachian Mountain Club, a Long Trail Mentor for Vermont's Green Mountain Club, and a Leave No Trace Master Educator. He lives in New Hampshire.
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26 comments

  1. Interesting stuff.

    One thing I’ve observed is that even trails that shown are often inaccurately placed. I think some of this is due to the fact that the 1940’s and 1950’s were when many of the maps were last surveyed on the ground.. Had GPS existed back then, I think that details like trails might have a much higher degree of accuracy in terms of their placement on the map.

    HJ

    • Exactly. More recent maps, especially electronic ones, have broken the different features like trails, roads, hydrology, etc. into separate digital layers that can be overlaid over a base map. For example, if you look at the current USGS National Map which is a base topo, it doesn’t trails or buildings.

      Trails also change, sometimes quite dramatically, resulting in reroutes, or closures.

      But back in the old days, the USGS paid people to go check and update those features. Now they don’t and leave it up to state mapping agencies and private groups to pick up the slack.

      • Alpinequest allows you to overlay maps in this way and includes access to some open source maps that I have found to be much more inclusive of unblazed trails and old roads. It is an android only app so a lot of folks can’t us it but it is a powerful well featured app for those of use who avoid apple products like the plague.

  2. I’m always amused (somewhat) and annoyed (somewhat) by the ones that have distances marked that are different from the distances on trail signs. I suppose one should use whichever distances are more recent given that mapping technology has much improved over the years, but sometimes there’s no good way to tell which is newer. But since these differences are usually only a couple tenths of miles, I am usually just amused rather than annoyed. Unless my feet hurt. :-)

    I also wish that that extreme close-up map of Washington you have here had topo lines on it but I guess that would be a lot harder to make.

  3. Some maps have deliberate little lies that mapmakers would include to identify copies of their maps. We have one training area where in one section the topography on the map is distinctly different than reality. So, we’ve wondered if that was one of those.

  4. Another thing that adds to map inaccuracy in rugged terrain is that the contour lines in the newer topoquads are generated by extrapolation from elevation point clouds derived from satellite data, which tends to smooth precipitous slopes, since it’s averaging between known elevations. You’ll rarely find contour lines stacked on top of each other any more. They might be closer together but you’ll be hard pressed to find the sheer drop offs. When I can get them, I use the older maps because the terrain at the scale I see when hiking is more accurate.

    • Last Sunday I ran into this problem when I tried to create a loop with a trail that was not located where the map said it was. This happens all the time and it is nearly impossible to have accurate maps of trails due to washouts, realingments, and recently built or acquired trails. Crowdsourced data is probably one of the best ways to update trail maps.

      • This! We can help ourselves.. choose a crowdsourced map data platform and upload GPS traces, and/or amend the maps with intelligence acquired on the ground. OpenStreetMap.org is a popular example; you can add and fix incorrect data.

      • Be nice if Gaia and other GPS makers exported tracks in a format that OpenStreetMap.org could absorb. It’s been a few years since I tried to import my tracks and I gave up because they had to be transformed on Windows machines (which has a huge pain in the ass). Has this been fixed?

  5. Andrew Kowalczyk

    Often the map routered into the signboard at the trailhead is the most accurate. Probably because it is made by someone who maintains the trail.

    • Not where I hike. 1) there are few trail kiosks even though I hike in a huge well-developed trail system and 2) those maps are often quite simplified or the same as what the public can access 3) it doesn’t do you any good if you can’t carry it with you.

  6. In other words, YMMV… Your Mileage May Vary.

  7. I think of it as three kinds of truth when it comes to distance. The first “truth” is what you roll (digitally or otherwise) off a map. The second truth is that info you obtain from guidebooks. The third truth is what you obtain from boots on the ground info from your phone or other GPS units.

  8. Road maps also lie. A few months ago, I paid for a state map published by a major mapmaker and used it to plan a trip home from Big Bend with a stopover at a certain state park, only to find they had the park’s location off by 50 miles. Driving my Will Rogers of RVs (which never met a gas station it didn’t like), I wasn’t about to make a hundred mile round trip backtrack to check out that park. Oh well, maybe next time I can plan the trip through there. The mapmaker refunded my money after I sent a copy of the receipt from the point of purchase.

  9. A rescue in October 2019 provides an excellent example of the hazards of using an “incomplete” map. A solo hiker left Pinkham Notch for a presidential traverse via the AT. The weather deteriorated after his departure, with high winds and heavy snow. He made it as far as Thunderstorm Junction before attempting to return to Pinkham Notch. He found that the snow on the summit of Madison was now waist deep, so he returned to the hut and dug in for the night. It was still snowing heavily in the morning so he pushed the “come get me” button on his SPOT satellite-tracking device. He was uninjured when the SAR team reached him several hours later, and walked out unaided, beating most of the SAR team down to the Appalachia parking lot. During the debriefing he was asked why he had called them; why he didn’t just walk down the Valley Way on his own? He answered “I didn’t know it was there”. His so-called map of the AT on his electronic device did not show connecting trails. The full description of this incident can be found in the Summer/Fall 2019 issue of Appalachia Journal.

    • That shows the need to be aware of all bailout routes when planning to hike a major trail. I think most of us have seen incomplete maps that are focused only on the main subject trail. It should be part of planning (but often isn’t… and I’ve been guilty as well) to get the full picture before embarking.

    • So, he only had an electronic map and nothing printed?

      • Silly…AT thru-hikers don’t need to carry maps. They just follow the white blazes. He was probably using the Guthook app which doesn’t list blue blazed side trails.

      • Hope you didn’t take that the wrong way. I think people should carry some sort of trail reference of the intersecting trails, but thru-hikers in the Whites are not very humble that way even though the locals know better. But signaling SAR, that’s pretty rude. Hope he got charged by F&G. Waist deep snow and no common sense to turn around and hike back down the way he’d come (up the Osgood trail presumably…past numerous signs)?

      • Thanks for the comments. Since you know Guthook, perhaps you could suggest he include the blue blazes for some reasonable distance to the side of the AT.

      • While I agree with you and will reach out, I don’t think the problem was the map. The hiker could have turned around. There’s also plenty of signage up there for exit routes as well as up to date forecasts at the Pinkham Notch Visitors Center. The hiker ignored all that and called out a frivolous SAR mission. Those people are volunteers and left their jobs and families to bail this guy out…for nothing. Sounds like he was a SOBO and would have seen the snow from miles away while hiking down the Carter Wildcat Ridge across the highway.

      • Yes, very true. The last time I was near the summit of Jefferson, I overheard a few thru-hikers talking about someone who got lost after going off trail and dropping their phone in a stream. Apparently, they had eliminated physical maps to go ultra-light.

      • Stupid light

  10. The USGS map is not the gold standard any longer. Other maps have surpassed that data, and while some USGS data may be included in the maps, additional trail and other information is also. I use an electronic map called Topo Maps Plus. It has many base maps and overlays to choose from and in my opinion the Natural Atlas is the gold standard for all kinds of navigation. To fill in the details only a picture can reveal you can overlay satellite imagery and adjust the transparency so that the photographic evidence of cliffs and other terrain features are visible with the topographic base map visible below.

    Using Natural Atlas I examined the Madison hut and surrounding trails. If it were possible in this post, I’d attach a screen shot. The AT and all the ancillary trails are visible. The aforementioned Valley Way, as well as the Airline, Airline Cutoff, Pine Link, Star Lake and Parapet trails are all shown on the Natural Atlas map.

    The only shortcoming of TopoMaps+ is the lack of a landowner overlay, of which nobody, not OnX or any of the pure hunting maps have good data for most of New England. The hunting apps originated in the West and that’s where the landowner data is solid. The folks at TopoMaps+ tell me landowner data is on the list. It’s not a big deal for hikers, but does matter for hunters and fishers.

    Being 65 and a Registered Maine Guide, I’ve got plenty of time behind a compass and paper map. The combination works if you are proficient but is an inferior anachronism now that electronic GPS driven maps are available, cheap and easy to use. With my iPhone map I can instantly locate myself, (something not easily done with map and compass lacking distinctive landmarks), I can mark waypoints to share or for future use hunting, fishing or camping, I can lay down trails in advance of bushwhacking then track the actual route I’m forced to take. Yup, I need power but that’s easy to supply with solar and a small battery. The camera on my phone eliminates the need to carry a dedicated camera. The waterproof case works. I’ve used the iPhone and TopoMaps+ in BC, MT, AZ and all over New England and been able to carry all those maps, all the time, easily accessible.

    If you have not yet examined a Natural Atlas topo map, or seen what you can do with imagery overlays, you owe it to yourself to have a look. The combination of TopoMaps+ and Natural Atlas deserve a review here.

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