My first big project on my GlowForge was to cut a Topo map that I had drawn in Illustrator by hand. It turned out great. However, going forward, I wanted to find an easier way to do this. After a quick internet search, I found a tutorial on how to make this process easier. Apparently, I’m an idiot, and there is a better way to do this, so I thought I would post the link here. This is not my tutorial, but I thought there might be others on this forum that want to give maps a go. I’ve already downloaded the maps for Wisconsin and have been going through the process to see if it really works.
Or just download GeoPDF’s from USGS, open them in Affinity Designer which maintains the integrity of all the layers, then select the layers you want to use. Process them in AD or Inkscape (which does not maintain the integrity of all the GeoPDF layers). A quicker solution if all you want is to use some of the vector or raster layers.
@timtsuga and I discussed this before as well.
Tl;dr: You can extract topo information from usgs maps using inkscape, you simply need to dig down through the grouped objects to get to it. AD seems slicker but I’ve still not tried it.
One thing I like about your process is the ability to set custom contour intervals. That’s slick.
I stayed up WAAY to late last night working on this. Here is what I found. I love the @timtsuga suggestion to use the USGS data, but unfortunately, this doesn’t solve my problem. This only gives me the contours for the land, and not the lake depths. Plus, the lake that I wanted to work on is on the corner of the USGS map, so I would have to merge 4 separate maps together in illustrator, which isn’t a simple process. The other limitation is that the State of Wisconsin cartographer’s office doesn’t have bathymetric (depth contour) maps available in a vector format. So, the closest alternative is flat PDF documents from the Wisconsin DNR. I can import these into Illustrator and then do a live trace on them to get the contour lines, but tons of clean up is necessary. Using a combination of the tutorial that I have listed in the first thread, plus using the flat PDF map documents from the DNR, I should be able to save myself some time. Other states may have this lake depth information available, but I haven’t checked yet.
A person’s area of interest is defined as “A geographic area that falls at the corner of four maps!”
It is called Cartographer’s Rule #1