I figured I'd make a tutorial on how I make district maps from boundary descriptions, with Michigan's senatorial map in use from 1983 to 1995 as an example.
Boundary descriptions are found in a few places; usually, these are passed statutes or legislative manuals. In Michigan's case, they are found in legislative manuals. The Michigan Legislature has made available the relevant portion of one of said manuals
here. There's also a
map, but it's mostly useful just for the northern part of the state.
First, I took a county map of the state in question that I had previously made, erased the borders between unsplit counties, and labelled the districts accordingly. Split counties were labeled with the districts containing them. Michigan tends to dislike splitting counties in its districts, so most states will likely be more complicated than this:
Next, I went through counties that are split between two districts and, using a township map on another layer, as well as online maps for naming reference, I drew the borders.
For counties that are more evenly split, I filled in a township map by precinct so that I didn't have to remember everything. This was also done for counties split more than two ways. Here is one such map:
Things started to break down when I reached Wayne County, as the city of Detroit was by necessity broken up into several districts. However, I marked down what I could by township. (I also had to make some of the labels smaller so as to fit well.)
Thankfully, Michigan describes the divisions of Detroit in a way that I can map out with the help of Google Maps. So I do that, taking a screenshot of Detroit and tracing on it along the streets and railroads mentioned in the description. Sometimes, this requires trying to figure out what a certain road has become. For one such case here, I had to look into the location of a now-closed weed dispensary which was the only recent thing left to keep the old name of a road that has since been renamed. At long last, however, I came up with this map:
This was thus copied and pasted onto the main map, scaled down and rotated to fit:
And traced over.
And so, the map is finished.