A lot of the midwest (or the great plains) is devoted to feed corn and corn for ethanol, wheat, and soybeans. It's not california where you'll find fields of lettuce, for example.

With that said, there's no shortage of small farms growing most anything that can be grown in the area, but they tend to not be exporting anything beyond the local farmers market.

> However, our estimates are for 2012, an extreme drought year in the Cornbelt. So, in another year, the network may look different. It’s possible that counties within the Cornbelt would show up as more critical in non-drought years. This is something that we hope to dig into in future work.

Have a look at Riverview LLP, one acre of land to grow food for one dairy cow each year. Plus crop rotation. Multiply by 15,000 cows in central Minnesota. https://www.riverviewllp.com/crop-production.html

also why isn't the central valley of California featured? pretty sure they produce more than los angeles county.