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NEW TNMCorps Mapping Challenge for City / Town Halls in IA & MN!

July 28, 2021

Here’s a new challenge for City / Town Halls in Iowa and Minnesota!

The United States Census Bureau lists almost 1,800 incorporated places in Iowa and Minnesota. Townships also exist in both states and may have their own designated building depending on the size of the community.  

As you can see from the map, city/town hall collection in Iowa is mostly complete so volunteers just need to go through and make sure nothing's missing. On the other hand, Minnesota still needs a lot of work.

TNMCorps Mapping Challenge: City/Town Halls in IA, MN
(Public domain.)

What does each point color mean?   

These colors are part of our tiered editing process and signal to other editors that a point has passed through the upper tiers and does not need to be edited again.  

Our November 2018 newsletter has an article titled Editor Roles and Point Colors that describes this process further.

TNMCorps Point Border Colors
(Public domain.)

Tips and tricks for this challenge:  

Local Government: Incorporated vs. Unincorporated 

  1. Incorporated places in Minnesota and Iowa consist of cities.  
  2. Townships also exist in both states, though they may not always have a designated township building. 
    • Only add a point for townships if they have their own designated building or space dedicated solely to township business. 
    • Do not add a point for shared spaces or private residences.  
    • See this Q&A for more on city/town hall meetings in other buildings.  
  3. The Cities vs. Towns vs. Villages article in our September 2019 newsletter elaborates more on the different types of governing bodies and how to determine if a point should be collected. 
  4. Also check out the What is a Township and the Township Government 101 flyers provided by The Minnesota Association of Townships or this publication from the state of Iowa for more on the nuances of township government in each state.  


Possible Sources 

Remember to confirm each entry in a list with an authoritative source (e.g., the city or village’s website) before using it to update the map. See the How to Spot an Authoritative (Re)Source article in our November 2017 newsletter for why this is important.   

  1. The United States Census Bureau has downloadable lists of all the incorporated places in each state by population. Here are the lists for Iowa and Minnesota.  

  2. The state of Minnesota maintains an online directory of cities and townships along with websites.  

  3. The League of Minnesota Cities also maintains a directory of member cities along with contact information and websites. 

  4. The Iowa League of Cities has a similar directory

  5. Wikipedia has lists of cities in Minnesota and Iowa

  6. The Minnesota Association of Townships maintains a directory of township websites by county.  

  7. Lists of Iowa townships are available on Wikipedia and in this spreadsheet provided by Iowa State University’s Extension and Outreach program.  

Smaller communities may not always have their own website and instead may use Facebook or other social media platforms for their virtual communications. See the newsletter article titled Social Media as an Authoritative Source (July 2020) for tips on when it is acceptable to use social media to update points.  


Proper Point Placement 

Our November 2018 newsletter includes an article on aerial interpretation for city/town hall structures. This article walks you through how to identify which building to place a point on when examining aerial imagery. 

Interested in collecting city/town halls elsewhere? 

We’re collecting city/town halls nationally, so feel free to research these features throughout the U.S.  There’s one last remaining state that still needs city halls collected, and that’s Texas.  Note that only city/town halls in Iowa and Minnesota will count towards this challenge.   


If you have any questions during the mapping process, reach out to us at and we’ll be happy to assist!  Thank you for all that you do, and happy mapping!