Trails and Graph Theory 22: Ground Truthiness

Ground Truth: Information known to be true by direct observation, rather than by inference. In GIS (Geographical Information Systems), ground truth refers to verifying or correcting data on a map database by going out and measuring.

Truthiness: Assertion that a statement is true based on opinion, without regard to evidence. (Coined by Stephen Colbert on the Colbert Report)

The 1.0 version of the Gila X Loop is not workable, and no one should attempt to hike this route in its present form. One key connector trail between Glenwood and Gila Hot Springs, Holt Apache Trail #181, is in questionable condition after a fire, likely very brushy with thorny locust. On my route #181 connects to Turkeyfeather Mountain Trail #102, which is completely removed from the USFS Gila Interactive Map, although it still appears on plenty of printed maps, CalTopo, GaiaGPS, and OpenStreetMap. Likely there are other trails on my route that are actually non-trails, permanently abandoned by the USFS due to serious damage after fire and subsequent erosion.

I will need to re-run my algorithm, after removing trails that are not on the Gila Interactive Map and no longer recognized by the USFS. Look for v2.0 of the Gila X Loop sometime in 2025-2026, along with an attempted thru-hike for even more Ground Truth.

On another matter, I encountered difficulty hiking on the Deloche/Winn Canyon Trail #179. My algorithm attempted to exclude “deloche and winn canyon” (case insensitive), but openstreetmap.org and most sources used the name “deloche/wynn canyon”. Computer programs typically look for an exact match when comparing strings. Oops.

Lessons Learned:

  • Programmers get caught up in the excitement of creating an algorithm, and do not allocate sufficient energy in vetting the input data. GIGO: garbage in, garbage out.
  • Geographical names may have slight variations. Do not use a string “equals” matching function for cases where a string “similar” function should be used.
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Author: Jim, Sagebrush

Jim (trail-name Sagebrush) codes audio software for Windows, Linux, Android, and embedded systems. When not working at sagebrush.com, he enjoys backpacking, which this blog is about.

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