Montana Digitization

[iandees]

Thanks for responding to my tweet about precinct map digitizing.

The Montana Democrats asked me to help them find/generate voter precinct GIS data and it sounded like fun. Like many states around the country, precinct maps in Montana are not stored in some standard format or place. In fact, there are several counties in Montana that just wing it or have such a low population that the whole county is one precinct. Our goal is to digitize the best data we can find and generate a statewide precinct fabric of precincts to offer as a pull request to Kelso's primary election data repo.

I see this as a three step system for each of the 56 counties in Montana:

1. Find voter precinct data for the county in whatever form we can
2. Georeference that data as best we can
3. Trace the georeferenced data into polygons and capture useful data about each precinct (the name or number, voting location for that precinct, etc.)

Here's the plan:

• The Montana Democrats have a Google spreadsheet and Drive folder that they've used to coordinate finding data by calling and emailing Montana county officials. They shared access to me and I'm copying what they have over to issues in my fork of Kelso's repo
• Counties that still need source material (step 1) have a "Needs Source" tag in GitHub. If you feel like Googling or calling, look at those tickets and track down source data from the county. When you find it, add it as a comment on the ticket and change the label to "Needs Georeferencing"
• Once data is found, it needs to be georeferenced (step 2).
  • In the case of a scanned document in a PDF, for example, I extract a PNG and load it into mapwarper.net to do the georeferencing. Include the link to the georef'd map service in the ticket and switch the label to "Needs Tracing".
  • In a few cases there are ArcGIS servers that have data on them. We need to extract the data out of those services (using pyesridump/esri2geojson for example) and attach the data to the ticket.
• Once we have georeferenced/extracted data, it needs to be traced (step 3). My plan was to use geojson.io to load up mapwarper's tile service and trace over the top into GeoJSON. If you're more comfortable using QGIS or an Esri product, those are options too. The end result should be a county's-worth of GeoJSON though.

Let me know what you think or if there could be a better way through this. I'd love to hear any suggestions!

Also, if this doesn't make sense or you don't feel like you know what some of this means, please let me know and I am happy to do a better job explaining.

[jbizzle]

I'm starting to try and work through these now and hopefully I can figure it out!

One thing to note is that the mapwarper.net website doesn't enforce HSTS (https://github.com/timwaters/mapwarper/issues/162), so just be on your guard and make sure to replace unencrypted URLs with encrypted ones (aka, change any http://mapwarper.net/... in your address bar to instead begin with https://.

This is particularly true when creating and confirming accounts, and when logging in.

[mvered]

In my experience, these counties will give you a GIS file of the precincts, if it exists, if you just email or call and ask them, so in many cases the steps on getting data from ArcGIS servers and pdf map files (aside from hand-drawn ones) should not be necessary.

I haven't had time to contact all the counties, but have the contact info for a number of county GIS departments if you someone else wants to take up this project. Here's the list: MT-GIS-Contacts.txt

For counties without GIS departments, you should generally be able to get at least a scanned map for each county from the elections office. Here's a list of email addresses for all the county elections offices in Montana: https://sosmt.gov/Portals/142/Elections/Forms/electionadministrators.pdf