Moat Mtn Trail Map Error

[peakbagger]

While doing a solo loop of North Moat on Saturday, I got turned around a bit due to a lack of blazing in the area and an error on the AMC map I was carrying. Due to the lack of blazes in the area and numerous paths and old logging roads, this is an area that does require some attention to follow the trail and could definitely be an issue to newer hikers.

Do note that the map was the "new" version (C1998), Map 3 Crawford Notch - Sandwich Range, prepared by AMC for the 26th edition (at least two WMG's old ). I probably wouldnt have posted, but later on in the day I stopped in at EMS and took a quick look at the white mountain map by Map Adventures and noticed the same error, so the error seems to have propogated. At the same time I checked the National Geographic Map and the USGS map and they show the trail correctly. The WMG guide written description accurately describes the trails correct location. It would be appreciated if someone with a newer version of the WMG, please verify if the error was corrected

Now on with the error. From the North intersection of Red Ridge Trail and the Moat Mountain trail, the Moat Mtn trail is shown to run roughly west along the north side of Lucie Brook until it crosses the brook to the south side west of where the Mt Mtn trail heads south away from the brook. It shows the Moat Mtn trail junction with the Attitash trail on the north side of Lucie Brook with the Moat Mtn trail immediately crossing the brook. Therefore,for me using the map as a guide (the book doesnt fit in the pocket very well), I would take the turn at the Red Ridge junction and hike along the North bank until I hit the junction of the Attitash Trail. If I crossed the brook, I would have gone too far and had missed the turn off. In reality in the field, the Moat Mtn and Attitash junction is on the south side of Lucie Brook and there actually was a crossing of Lucie Brook (marked with wooden arrows) east of the junction.

What I did Saturday hike along the north side fo the brook and crossed the brook from North to South assumed that the Mt Attitash trail had continued on the north side of the brook (but was unsigned and unblazed). At that point I assumed that I was on the North Moat trail but after following the brook for about 15 to 20 minutes past the crossing, stopped looked at the map and determined that the trail didnt line up with the map and that I was on the Attitash trail and had gone far past the Moat Mtn cut off, I then and hiked back, crossed the brook and looked intently for the Moat Mtn turn off all the way to the to Red Ridge trail, which I then hiked and did the loop clockwise. Of course, coming down Moat Mtn trail I encountered the junction with the Attitash trail (with a brand new sign) on the south side of the brook and after hiking just around the corner saw where I had turned around. (what the heck I was out for exercise)

Considering that the new AMC maps was reputed to have been double checked with GPS and field measurements by AMC staff, it would be interesting to note how this error got introduced back in 1998 and how long it was propogated, as prior versions of the map show this correctly (although difficult to read as its on the border of the map).

So does anyone have the most recent AMC guide versions and maps to verify that this mistake was corrected? Otherwise, I will gladly officially contact the WMG editors (although I think one of the lurks here on occasion).

 

[peakbagger]

Good so that means AMC caught it at some point. I will send Map Adventures a heads up and justify my purchase of a new WMG.

 

[1HappyHiker]

Below is the text (as contained in the current WMG) which describes the portion of the route that I think you are questioning.

“The Moat Mountain Trail crosses Lucy Brook (difficult at high water) at 1.4 mi, and follows the south bank, then at 2.4 mi, turns abruptly left uphill, away from the stream (last sure water), at the point where the Attitash Trail continues straight ahead along the stream toward Big Attitash Mountain.”

Below is a snippet of the trail map from the current WMG (the Moat Mountain Trail is highlighted).

 

[1HappyHiker]

(My vision has blurred somewhat in the past few minutes from looking at that section of the map!)

I know what you mean!
Below is a blow-up of that portion of the map.

 

[jniehof]

Considering that the new AMC maps was reputed to have been double checked with GPS and field measurements by AMC staff

Many of the trails were GPS-measured. The base map is still USGS-derived, which can "move" a stream and create or obliterate crossings. An infallible cartographer will catch all such occurances. A merely excellent cartographer will miss some.

Both my 27th and 28th edition maps show it correctly (although I think it's actually clearer on the 27th.)

For a similar error, look at the Snapper/Gorge Brook junction on Moosilauke. The 27th edition map clearly shows the trails splitting and each separately crossing the brook, when they actually split just after a joint crossing. The 28th shows...I'm not sure what. The heavier line used for trails on the 28th edition map makes a mess of this sort of thing.

 

[psmart]

There are complications with higher-precision GPS mapping! We had this type of problem when the GPS work was done for the latest WODC map: There are places where the trail now appears to be in the wrong location in relation to other features taken from the USGS base map. The only way to correct this is to GPS the natural feature (such as a stream, which is difficult and time-consuming), or "adjust" the trail position in order to show the correct relationship to the natural feature.

 

[RoySwkr]

There are complications with higher-precision GPS mapping! We had this type of problem when the GPS work was done for the latest WODC map: There are places where the trail now appears to be in the wrong location in relation to other features taken from the USGS base map. The only way to correct this is to GPS the natural feature (such as a stream, which is difficult and time-consuming), or "adjust" the trail position in order to show the correct relationship to the natural feature.

Part of the problem is that at many map scales the trail and brook are much narrower than the width of the line used to show them, so if displayed correctly a trail near a brook would be essentially on top of it. Since you are already messing with accuracy by showing the trail and brook too wide, it is relatively harmless to do like WODC and move the wide lines farther apart to show their correct orientation.

When my sister was GPS mapping for the USFS in CO, she would take a point at each crossing or similar feature so she would know where to show the crossings on the map. Using the track log alone doesn't work as explained above.

 

[sardog1]

When I teach navigation, I tell students that there's one sure sign that they know what they're doing: When they find an apparent map error and can convince themselves that's what it actually is, by comparing the map with the ground.

This example is why it's always a good idea to follow your progress on the map. When you encounter a map error, it will thus "usually" become apparent fairly quickly.

 

[psmart]

Part of the problem is that at many map scales the trail and brook are much narrower than the width of the line used to show them, so if displayed correctly a trail near a brook would be essentially on top of it. Since you are already messing with accuracy by showing the trail and brook too wide, it is relatively harmless to do like WODC and move the wide lines farther apart to show their correct orientation.

Unfortunately, we encountered some errors in the USGS stream locations that were considerably larger than the line widths on the map. There were even some missing stream segments, such as the south (primary) outlet of Flat Mtn Pond, and incorrect stream locations such as Whittin Brook near Paugus Mill. These errors were propagated onto the AMC and WODC maps for many years, but you'll find them corrected on the latest WODC map

Based on these specific findings, I'm sure there are other stream mapping errors away from trails where they're not as readily apparent.

 

[sardog1]

Unfortunately, we encountered some errors in the USGS stream locations that were considerably larger than the line widths on the map. There were even some missing stream segments, such as the south (primary) outlet of Flat Mtn Pond, and incorrect stream locations such as Whittin Brook near Paugus Mill. These errors were propagated onto the AMC and WODC maps for many years, but you'll find them corrected on the latest WODC map

Based on these specific findings, I'm sure there are other stream mapping errors away from trails where they're not as readily apparent.

I remember a search on Monadnock during which I abandoned all reliance on the map for stream locations.

 

[peakbagger]

A bit of a tangent to my original thread, but since we drifted into the map versus the field what the heck.

In 1997 before the NE ice storm I did an fairly extensive project to digitize a portion of a local towns zoning maps and overlay their trail network to see which property owner had trails running on their property. Just getting the detail maps to line up with the index maps proved to be a "challenge" and compromises were made.

When the results were published at a club event, several of the old timers in the area insisted that the final map was wrong and that the trails didnt run on the properties where the overlay showed them to be. At least a portion of the trails had been located with GPS and I had used USGS orthophotoquads to correct key locations where the tax maps didnt line up, therefore I felt fairly comfortable that the trails where correctly located. Rather than get the locals upset, the project was deemed for "management use" by the club. The next winter, post ice storm, I got to spend a lot of time helping to clear the trail network in several of the areas of contention, and when I had the time, I would compare various land surveying pins that I encountered with my map. In the majority of the cases, what was in the field lined up with my map so I felt vindicated. As for the local experts, some times its best to avoid throwing rocks at a hornets nest

I used to do surveying in college and I learned that the surveyors judgement comes into play a lot more often than people would think. The old farmers who sold most of the land just werent that accurate (or necessarily honest on occasions) and its hard to identify an exact location in the present when the deed refers back through more than 200 years of land tranactions to the easterly boundary of "widow Moody's dower" (One of the key deeds of Scarborough Maine).

The map is still around but its maintenance was handed off to someone else. I see a version on occasion hanging up on a wall being used for "trail maintenance".

 

[sardog1]

I used to do surveying in college and I learned that the surveyors judgement comes into play a lot more often than people would think.

I heard a rumor once that large parts of the field work for the first survey of northern Minnesota were done in local taverns and not in the bug-infested swamps.

 

[RoySwkr]

Based on these specific findings, I'm sure there are other stream mapping errors away from trails where they're not as readily apparent.

Note that the outlet of Kinsman Pond is on a different end in the 15' vs 7.5' maps, and it is the 15' that is correct. Also compare Pine Bend Brook as shown on the map to where the major brooks actually are and which one is labelled at the road

But even if the streams were correct the map would often be useless if accurately drawn particularly allowing for slight offsets in color layers.

The old farmers who sold most of the land just werent that accurate (or necessarily honest on occasions) and its hard to identify an exact location in the present when the deed refers back through more than 200 years of land tranactions to the easterly boundary of "widow Moody's dower" (One of the key deeds of Scarborough Maine).

If you don't pull the chains tight (hard in woods) you can measure out more land than there is

Land wasn't worth much years ago and so there was less need for surveys to be precise. One guy I knew got into a fight with his neighbor over a few feet - turns out that an old deed on one side of the line that read "N rods more or less" got rewritten as "XX.5 feet more or less" somewhere along the line without any actual survey.