Richland Chambers Reservoir shows up as "Corsicana River" on terrain data. I asked around and was told that 20+ years ago that was the name of the river before they broke a dam and extended the area. Perhaps the data being used to map terrain areas is quite old?
Google hasn't spent the time to go through and prioritize the labels. I imagine they could do this fairly automatically with their web index, but it's still a fairly large chunk of work for a relatively small benefit. I'm sure most people hit the maps from a search, not just to drag the map around and critique the labeled markers.
<i>I’m puzzled by Google’s labeling decisions on their "Terrain" maps.</i><p>Replace "Terrain" with anything else and that's pretty much the subject of all of this blog's entries. I don't know why the naming on the terrain maps would be any better than the labeling on any of the other map modes.
If Google can distinguish references to different features with the same name on web pages, then Google should rank features by number of references on the web and label accordingly.
You can report mistakes (<a href="http://maps.google.com/support/bin/answer.py?hl=en&answer=162873" rel="nofollow">http://maps.google.com/support/bin/answer.py?hl=en&answe...</a>). I reported one once... about 6 months later received an email from google saying it was fixed... it was. Of course a wikipedia-API would be awesome. Google usually likes things like that: <a href="http://images.google.com/imagelabeler/" rel="nofollow">http://images.google.com/imagelabeler/</a>
It has actually improved, I think. They used to label weird little water features even at fairly zoomed out levels. You'd see a map of some state and see "Level Ditch #4" in the middle of Oregon or Idaho or something.<p>Incidentally, I think Google Maps is one of the coolest things ever... I used to love to look at USGS quad maps as a kid, and now I get something that is 80% as good for pretty much the entire world. How cool is that...
I don't think the terrain tiles get much attention. For a while it was really excited about irrigation ditches, then a few months ago lots of river rapids showed up.
Hopefully they'll make the relief shading layer available in styled maps at some point.
Could it be that these terrain maps are compiled from hiking maps, which tend to be very local and don't label obvious or general features like "the Nile" or "the Alps"?