[Cdt-l] quad maps unnecessary

[Bob Sartini]

Definitely right that some of them are quite old. My local one in Vermont
is very out of date, maybe 20 years.


On Mon, Jan 27, 2014 at 3:12 PM, Jonathan Ley <jonathan at phlumf.com> wrote:

> I was just going to point that out – my maps are just the USGS 1:24000
> “quads” with CDT-specific info overlaid onto them. So, when you print them,
> they come out to ~1:60,000 on a 8.5 x 11 sheet of paper. Of course some of
> the fine detail is hard to read, but it’s all there. Plus, these are all
> spliced-together, so they’re a bit more efficiently cropped.
>
>
>
> The original USGS quad sheets are quite large. They’re neat to look at,
> but not quite so practical in the field. (In addition, murphy’s law
> dictates that whatever location you’re interested in will be right on the
> corner of a map, meaning you need to line-up 4 of them). Anyway, you can
> download them from the USGS – they’re open-source items… so, if you have
> access to a large-format printer, there you go.
>
>
>
> However, my understanding is that the USGS is no longer updating the
> traditional quads (also called 7.5  minute maps). Instead, they’re focusing
> on providing layered digital mapping information to fulfill their mission.
> I think they made this change about 10 years ago, but some of the quads are
> quite a bit older. I can understand why the USGS would do this, but it
> still sucks for those who aren’t doing professional GIS mapping… and the
> old quads get more and more dated. The land might not change, but some
> things do – the shapes of glaciers and forests… And there is a lot of
> useful man-made information on the quads – primarily roads & trails. It
> might possible to “reconstruct a quad” with the latest digital data & the
> right software tools… I haven’t really looked into it, but I bet someone
> somewhere has done a blog post about it J Anyway, that’s all just my
> understanding of the situation… Not sure I’m 100% correct on this.
>
>
>
> -Jonathan
>
>
>
>
>
> *From:* cdt-l-bounces at backcountry.net [mailto:
> cdt-l-bounces at backcountry.net] *On Behalf Of *blisterfree at yahoo.com
> *Sent:* Monday, January 27, 2014 10:21 AM
> *To:* Continental Divide Trail
> *Subject:* [Cdt-l] quad maps unnecessary
>
>
>
> USGS 1:24000 isn't about the specific scale so much as the level of detail
> depicted in the series. And the detail isn't so much about man made
> features, which can change or have inaccuracies, as it is the topography
> and hydrology, which are more or less static and the main focus of
> navigation. I believe Jonathan's maps are portions of USGS 1:24000
> digitized maps at a sub-40% scale reduction. Of course what makes them work
> is all of the work he puts into them to show the route options and
> suggestions for travel. The fine map detail and the CDT-specific add-ins
> work synergistically to make the product the wonder to behold that it is.
>
> Brett
>
>
> Sent from Yahoo! Mail for iPhone
>
>
>
> _______________________________________________
> Cdt-l mailing list
> Cdt-l at backcountry.net
> http://mailman.backcountry.net/mailman/listinfo/cdt-l
>
>


-- 
Everything is in Walking Distance
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.backcountry.net/pipermail/cdt-l/attachments/20140127/2ddc0d38/attachment.html