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I stumbled upon the map of Yellowstone National Park on OpenStreetMap:

enter image description here

Is there a particular reason for this map to be so strange?

  • the borders of the park cut off the "forest" marking, right through the borders
  • the inside of the national park is almost empty, the roads are not marked, the village is missing, etc.

What is particularly enigmatic to me is that this is a very touristic area and I would expect it to be very well updated.

I checked for instance Zion National Park or the Grand Canyon and they are rich in information. I also had a look at Yellowstone on Google Maps and there are plenty of details.

WoJ
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2 Answers2

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In reference to your observations:

the borders of the park cut off the "forest" marking, right through the borders

The surrounding areas in green are National Forests, which are a different administrative unit than National Parks.

the inside of the national park is almost empty, the roads are not marked, the village is missing, etc.

This is an issue of scale rather than content--Yellowstone is simply huge compare to the National Parks you reference. OSM is a dynamic service, where content changes with scale. If you increase the map scale, all of the features become apparent. For example, here is a screenshot of the Canyon Village:

enter image description here

Aaron
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  • You are right, I did not realize how big the area is. I was scrolling down somehow, but not enough. – WoJ Mar 28 '17 at 06:55
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The forests in your screenshot have been imported from the National Hydrography Dataset (NHD). This is the reason for their unnatural shape.

Many imports, especially in the US, have been performed in the early days of OSM. Meanwhile most imports are discouraged for obvious reasons.

The OSM community in the US isn't as active as in other countries (probably also due to these imports). Therefore nobody has fixed/updated the landuse polygons in this area yet.

Feel free to improve this area. You can get more information about contributing to OSM by visiting learnosm.org and by taking a look at the beginner's guide.

scai
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  • Thanks for the update on the imports. Could you elaborate on the reasons why imports are discouraged in the US? I do update OSM frequently, but since I am 10,000 km away from Yellowstone it won't be easy to help there :) – WoJ Mar 28 '17 at 06:58
  • Imports are discouraged worldwide for OSM. Some of the reasons are listed in the import guidelines. The main reasons are that imports have to take care not to duplicate existing data or degrade their quality. Also various previous imports have been of poor quality (regarding accuacy and/or tagging). This has lead to significant work for fixing this automatically imported data compared to deleting/re-surveying it manually.

    Regarding your distance: you can still trace landuses with the help of aerial imagery.

     – scai Mar 28 '17 at 07:17
  • Thanks for the info. I was wondering about that as I recently saw quite a lot of imports being done around the place I live in (Paris, France). – WoJ Mar 28 '17 at 09:19
  • Are you sure that these are imports? Either way, there are still a few imports getting accepted after having been discussed by the OSM community. They are usually of a better quality and lots of work is done for avoiding duplicated data. – scai Mar 28 '17 at 09:25
  • Yes, they were imports from the French cadaster to put better building/terrain limits in places where the data was manually (and roughly) put in place. – WoJ Mar 28 '17 at 09:28
  • This is a very carefully handled import as far as I know. See https://wiki.openstreetmap.org/wiki/FR:WikiProject_France/Cadastre for more information. – scai Mar 28 '17 at 09:29