Glad you had an enjoyable hike, especially with the foliage starting to turn in this area.Without knowing the specifics of your GPS device and its settings (I'm not sure how MapMyHike operates exactly), it is difficult to pinpoint the cause of error, but we are fairly confident of the 4.5 mileage for this hike loop based on a couple factors:
- Our Geographic Information System (GIS) database of trails, from which our maps are produced, is able to calculate straight-line and elevation-adjusted distances. These GIS-derived distances match fairly closely with the 4.5 miles listed for this hike.
- GPS measurements are prone to a wide variety of errors. GPS data can be extremely useful, and we use it to create our trail maps, but due to different kinds of technical issues/errors/settings, one should exercise some caution when referring to its data. As a personal anecdote, I recently GPSed the same section of trail with two different GPS units, and after 5 miles, there was a 0.5 mile difference between the two! Satellite configuration, amount of clear sky, GPS chipset, and configuration settings are likely the most common places where GPS error can be introduced.
So I'm not quite sure how an additional 1.8 miles of distance was incorporated into the GPS log of your MapMyHike app, but I'm guessing it is some combination of factors mentioned above. However, thank you for commenting about this, as your word of caution allowed us to double-check the mileage number just to make sure.~JeremyTC Cartographer