Another factor is that some of the meat packing plants are in states that have not adopted many (or any?) measures to slow community transmission of the disease.
Maybe some of them. KS has had a shutdown, statewide, for at least the last 30-45 days. There are a couple of outbreaks centered around meat packing plant facilities.
https://www.coronavirus.kdheks.gov/160/COVID-19-in-Kansas
Look in s/w KS (largest city, and total county population):
Ford Co (Dodge City) pop 34000, has a National plant
Finney Co (Garden City) pop 36000 has a Tyson plant
Seward Co (Liberal) pop 21000 - I'm not sure what their connection is to the outside world, but I *think* they have some connection to the beef industry as most counties out there do.
There are a couple of other counties in the center that show higher than the rest of the state:
Sedgwick Co (Wichita) pop 512000
Lyon Co (Emporia) pop 33000
With the >10x population of Sedgwick Co compared to the rest of the above counties, I'd expect a greater number of positive cases.
I'm not sure what's going on in Lyon Co, though.
It's also possible that these numbers are related to the number of tests each county has done.
The other counties in the N/E are either suburbs of KC, have large prison populations (Leavenworth), or were hit especially hard in nursing homes. Two of those counties, Johnson and Wyandotte, are shut down for an additional week even as the State reopened yesterday.
edit:
Lyon Co (Emporia) pop 3300 has a Tyson plant
Seward Co (Liberal) pop 21000 has National plant
So, the major breakouts in my state are centered around meat plants and locations with prisons and nursing homes.