Map #8: October 3, 2016

Difficulty Level: 7

Click here for a full-size version of this week’s map.

This map is a choropleth of the United States. (Do you need a refresher on what a choropleth is? Visit our “Basics” page for a quick primer.) On this map, each county is colored in reference to a particular statistic. This week is our first with a choropleth that features two different colors—in this case, pink and green. There’s a reason for that! Your job for this week: figure out what statistic is represented by this choropleth.

Stumped? Check back Tuesday, Wednesday, Thursday, and Friday for hints about where to focus your investigation. The answer will be posted on Monday, October 10. Good luck!

General warning: Be specific this week! Your answer should explain both colors. A complete answer will also include a time frame—you don’t have to get it exactly correct, but you should be able to get pretty close.

Tuesday’s hint: As always, one good place to start with a choropleth is by noting the outlier counties and trying to learn about them. Let’s start with the greenest county in Texas: Terrell County, home to the county seat of Sanderson. Look around and see what you can learn about the history of Terrell County.

Wednesday’s hint: Yesterday’s hint referred to a dark green county in Texas; today’s is about the dark pink counties in Texas. Look at the area around the cities of Midland and Odessa, just to the east of the Texas–New Mexico border. Midland and Odessa are centers of the oil industry, and both of them are places where a lot of fracking has taken place in recent years. What else can you learn about these places that might be relevant to solving this week’s map?

Thursday’s hint: Like yesterday’s hint, today’s hint is about an oil boom. Presumably, you have noticed that the biggest patch of pink on this choropleth is in the western part of North Dakota. That region has benefited from the discovery of oil in the Bakken Formation. Take a moment to consider why two of the most extreme colors on this map are in regions that are home to a significant oil industry. What impact has the ability to access this oil had on the communities in these areas?

Friday’s hint: Most of the counties that contain big cities are colored pink on this map. The best way to solve one of our choropleths is generally to look for exceptions to general trends. So for today’s hint, we’re pointing out two of the only counties that are home to big cities and colored green on this map: Cuyahoga County, Ohio (which contains Cleveland), and Wayne County, Michigan (which contains Detroit). Here is this week’s big question: what is something that Detroit and Cleveland do not have in common with nearly other large city in the United States?

Answer: Click here to see an explanation of the answer to this week’s map question.

Next map: Click here to try out our newest map question.