Upon looking things up scratch Rapid City, it actually has some prominent Biden precincts around downtown...Casper actually has a tied precinct but none actually won by Biden. Abilene, TX is one that would work though.
Also both Dodge City and Garden City have Biden precincts in prominent locations so probably not many in western Kansas actually.
Central Nebraska around Grand Island, Kearny, Hastings has no Biden precincts. So easily a person from Grand Island, it self. Biden’s best precinct is Trump +5.9. I can easily imagine a young professional who moved there for family that voted for biden but hasn’t left the area as they don’t have reason to. Grand Island has a small restaurant science, a small water park, supermakets, and a few hospitals. It’s easy to imagine someone not leaving for months at a time.
The nearest precincts are either in Lincoln or Lexington