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Craig W.
(xnomanx) - F - M
Free USGS Maps and UTM Coordinates on 11/20/2011 21:19:50 MST Print View

Thanks to a generous friend, I just recieved my first GPS unit. One of my main interests in using it backpacking is to use the UTM system on USGS quadrangles (which can be downloaded free).

But I'm not too tech saavy...

Any advice on the best way to print sections of USGS maps while still preserving scale and/or usable UTM coordinates? One pain of the USGS maps is that they include UTM coordinates, but not a grid...So I'm trying to figure out how to print them in a way that will allow me to use a UTM overlay grid, corner ruler, or simply add my own UTM gridlines, etc...

I know that Tom Harrison includes UTM grids on many of their maps and I could buy those (or full size USGS maps), but I'm hoping there's a simple way to take advantage of the free USGS maps available through the computer and combine them with the GPS/UTM system.

drowning in spam
(leaftye) - F

Locale: SoCal
Re: Free USGS Maps and UTM Coordinates on 11/20/2011 21:38:16 MST Print View

Basecamp works well.

John S.
(jshann) - F
Re: Free USGS Maps and UTM Coordinates on 11/21/2011 05:44:52 MST Print View

It can be work, but it's sorta fun to me.

1. download quadrangles
2. draw in gridlines using graphics app (graphicconverter for mac)
3. figure out the four corners (utm coordinates) of map (most will include more than one quadrangle)
4. crop each quadrangle to just what is needed
5. open new image, paste all cropped images into it, line them up, crop out excess, save
6. figure out how many sheets of paper the new map will need to be printed on, then crop again for each sheet
7. type in utm coordinates and verify they are correct (see original quadrangles)
8. print each sheet

I don't worry about scale too much. If you are solo and/or offtrail hiking, you really need 1:24k. The typical scale on my sheets is around 1:50k. You can calculate your map scale by measuring the distance between the kilometer marks and plugging it into the scale calculator at Oregon State University.

It would be nice if Hillmap (or somebody else) built this functionality into their website so you could just type in the UTM coordinates of the four corners of your map and download the map with a UTM grid already overlayed. I don't think it would be that hard for a programmer to do this. GMAP4 has added a UTM grid overlay feature.

Edited by jshann on 11/21/2011 07:55:37 MST.

Craig W.
(xnomanx) - F - M
Re: Re: Free USGS Maps and UTM Coordinates on 11/21/2011 11:43:39 MST Print View

Sounds like I could open the map images in Gimp (what I've been using for imaging), snap some UTM grid lines across them myself, label the lines with coordinates (or label the bottom corner of my printout), and then print sections from there.

You're right...I guess accurate scale doesn't really matter in my prints as long as the grid is already there and I can see topo details.