The 5 U.S. Counties Where Racial Diversity Is Highest—and Lowest

Why are Alaska's Aleutian Islands so racially mixed? And other questions from a new map of U.S. populations.

Data wizard Randy Olson, the guy behind that astounding graph illuminating the reality of paying for college with minimum-wage work, has created another beautiful visualization: a map of racial diversity across the United States' nearly 3,000 counties.

He had been looking at these other maps depicting specific demographic densities by county:

Latino population by county (%), according to the U.S. Census Bureau (Devinn Jani)
African American population by county (%), according to the U.S. Census Bureau (Devinn Jani)

There are three more of those—for Native American, Asian, and white (non-Hispanic) populations. But Olson wanted to combine the data to see how and where the different demographics mix. He ranked the counties according to how evenly split their populations were between the six categories of race tracked in the census.

Each county has a breakdown of race by percentage—i.e., Montgomery County, Maryland, is 49.3 percent white, 16.6 percent black, 0.2 percent Native American, 13.9 percent Asian, 17 percent Latino, and 3.1 percent "other." Olson quantified diversity by calculating entropy for each of these sets. He explains it on his blog like this: "A county will come out with high entropy when all six ethnic categories are as even as possible (i.e., each ~16.7 percent), whereas it will come out with low entropy if the county is only inhabited by people of one ethnic category."

Like the nation's population, the results were mixed. Some things weren't surprising at all, like the fairly homogeneous swaths of the Northeast and the Midwest. Vermont looks to be the least diverse state in the nation. The least diverse county, according to Olson's calculations, is in West Virginia, followed by two counties in Kentucky and ones in Nebraska and South Dakota.

What may be more surprising is where the high-diversity pockets are: in major cities, yes, but also in Alaska, apparently. Two counties there rate higher on ethnic entropy than Queens County, New York.

For what it's worth, when asked why he thought Alaska took the top spots, Olson suggested: "The Aleutian Islands have a fairly small population (~5000 people) and are home to several fishing ports in Alaska," he said. "Deadliest Catch comes to mind... perhaps such a dangerous job draws in people from all backgrounds to come work and live there?"

Al Jazeera America reported in January that the aptly-named town of Unalaska, Alaska, part of the Aleutians West Census Area, has in fact seen an influx of "young, diverse" inhabitants—as it turns from a fishing community into a hub for oil drilling.

The 5 most diverse counties in the U.S., according to Olson's calculations, are:

  1. Aleutians West Census Area, Alaska (31.4% white/non-Latino, 5.7% African American, 15.1% Native American, 28.3% Asian American, 13.1% Latino, and 6.4% other)
  2. Aleutians East Borough, Alaska (13.5% white/non-Latino), 6.7% African American, 27.7% Native American, 35.4% Asian American, 12.3% Latino, and 4.4% other)
  3. Queens County, New York (27.6% white/non-Latino, 17.7% African American, 0.3% Native American, 22.8% Asian American, 27.5% Latino, and 4% other)
  4. Alameda County, California (34.1% white/non-Latino, 12.2% African American, 0.3% Native American, 25.9% Asian American, 22.5% Latino, and 5.1% other)
  5. Solano County, California (40.8% white/non-Latino, 14.2% African American, 0.5% Native American, 14.3% Asian American, 24% Latino, and 6.2% other)

And the 5 least diverse:

  1. Tucker County, West Virginia (100% white/non-Latino)
  2. Robertson County, Kentucky (100% white/non-Latino)
  3. Hooker County, Nebraska (100% white/non-Latino)
  4. Hand County, South Dakota (99% white/non-Latino and 1% Latino)
  5. Owsley County, Kentucky (98% white/non-Latino and 2% Latino)

As to what surprised Olson the most? "As a Michigander," he writes, "I’m the most surprised to see how diverse the Upper Peninsula is. I thought only crazy white people lived up that far in Michigan."

Svati Kirsten Narula is a reporter for Quartz.