USGS Fail!

[aiwetir]

I'd love to see that map again without spending that $8 USGS wants for the old maps.

I believe you can download most, no?

Every time I look they want $8 for the map I want, but today they seem to be free. Unfortunately I cannot find the error on USGS maps 15 years later perhaps it was a USFS map.

[VanMarmot]

Part of this is inherent in mapping in general. Because the 'standard' USGS quads are 7.5" maps, they're covering 7.5 minutes of latitude and longitude, and are slightly trapezoidal, and will cause some alignment issues when you try and stitch them all together.. The whole flat faces on a spherical surface bit.. It's also good to be aware that different maps have different contour intervals, so your topo lines may double, or half, at the borders.

It's easy to tell in the steep face, but can look more like an alignment problem in the flatter areas unless you pay close attention to the contour interval and realize it shifts from 40' to 80'

Years ago, I was working in northern Alaska and we were issued paper maps (yes, this was before GPS) and they were truly trapezoidal!

My map join comment had more to do with aligning quads with either different contour intervals (as you note), of different ages (adjacent quads may be 10 years or more apart in terms of when they were last finalized), or final and provisional maps. All this is what has kept map reading and navigating so interesting for so many years!

[aiwetir]

I cannot locate the error I once saw on my USGS quad so I replicated it after a little bit of hard remembering. The section of stream between the arrows didn't / couldn't exist although topographically it looks plausible on this map.

[VanMarmot]

I cannot locate the error I once saw on my USGS quad so I replicated it after a little bit of hard remembering. The section of stream between the arrows didn't / couldn't exist although topographically it looks plausible on this map.

download.jpg

Good one! Either a real error or some kind of diversion canal mapped as a creek?

[aiwetir]

Good one! Either a real error or some kind of diversion canal mapped as a creek?

That was a real error. I surveyed both of those streams, Jimmycomelately and it's tributary that runs north into it along the section 26/27 line (that line isn't on the map). The confluence of those streams was actually where it looks like they could run together if they didn't put a curve in the one stream. It was confusing trying to find the confluence in real life since the map was almost 1/4 mile off and there was another small stream 1/4 mile east, we just made an educated guess and went for it.

[retired jerry]

I looked at a couple versions from gps store and none of them had it

[aiwetir]

I looked at a couple versions from gps store and none of them had it

Yeah, I looked at all years and even some USFS ones, I didn't see it, but since I had to find that confluence in real life, I remember the map well. My work partner and I both got a kick out of it at the time. I'm not sure where our map came from though. I wonder if the DNR had some strange maps sitting around.

[Lurch]

Coulda been an old provisional map. Even the USGS historical map resources rarely put up provisional versions

[kepPNW]

Just puzzled over this, for a moment... Not USGS, but another entity that has typically taken pride in their cartography.

This is from National Geographic's "Columbia River Gorge National Scenic Area" map, #821.

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  See the problem?

[retired jerry]

mt st helens national volcanic monument?