Issue: Missouri River Boundary Anomaly
I recently did a custom tile for a good chunk of the Central, Midwest and the Great Lakes region of the United States. I’m planning a trip soon, and I’m going to be visiting a number of areas, including South Dakota (this is as far west as I selected.)
Roughly speaking, the tiles cover Missouri (my home state), part of Nebraska, South and North Dakota, Wisconsin, Minnesota, Michigan and the entire Great Lakes, Illinois, Indiana, Ohio, and Arkansas (the southernmost part of the entirety of the tiles.)
This is my problem: Near the center of Missouri, near the town of Jefferson City (ironically, my city of residence,) I found, to my chagrin, that a good chunk of the Missouri River is a solid blue. I found this anomaly on my Garmin Dakota 20 GPS.
Please note the upper (northern) boundary line of what shows as “Missouri River.” A pop-up appears when hovering the cursor over an open, blank area of the blue area, when doing so in Base Camp. I took the following two screen shots of the Base Camp interface to illustrate the anomaly:
http://www.panoramio.com/photo/72790350
http://www.panoramio.com/photo/72790355
Again, Upon finding this issue on the Dakota 20 GPS, I opened Base Camp, selected my OSM World Routable map product, and found the same map anomaly. The bottom (southern line) of the Missouri River is correct. However, the northern part seems to have been turned into what appears to look like a widening-out of the river, as though on a flood plain.
The northern-most line runs (starting from the upper left of the anomaly, near the town of Lupus, Missouri) from east to west for about 14 miles. (14.4 miles using Base Camp Measuring Tool.) From there, the upper-boundary-line goes in an East-By-Southeast direction for a fairly long stint–about 76 miles (76.3 as measured using Tool,) then goes south about 3 miles (3.3 as Measured using tool) south, back to the Missouri River.
I can tell you that this is not the normal course of the Missouri River.
Now, the flood plain does go a bit northeast of Jefferson City, Missouri, and flooded extensively in a well-remembered flood of 1993. Still, this is not the case today, as a town to the immediate east of Jefferson City–Holt’s Summit, MO, across the Missouri River via the US-54 bridge–is quite high in elevation, and the Missouri River would have to reach a flood stage of Biblical proportions to have represented on the map the northern water boundary lines as indicated.
As I was typing this, I redid the map regions and downloaded a new installer file. I installed the new one, and the anomaly still appears in Base Camp. I’m going to download the gmapsupp zip file, transfer it directly to my gps, and see if the anomaly is visible on my Dakota 20. If it is, I would say that the map build process is messing up some hydrography data with some type of other boundary line, or the tile-merge is doing something weird.
Well, that’s it. I appreciate your hard work on these maps, and am enjoying using them. If you need any assistance with the tracking down of the problem on my end, please let me know what I can do and I would be glad to oblige.
Leaving you with my,
Warmest Regards,
Stephen A. Brown
Jefferson City, Missouri