I would love to know so I can keep it realistic. If you can try to list the airplanes that are only used now.
The United CRJ-200 is all I can find
If you’re looking for what’s being used at the exact moment, you can check Flightradar24 or Flightaware.com for any route
There’s also an occasional 738 from United (they do it for repositioning).
Delta also operates an E175 and American operates a CRJ-700 on this route.
For a while I thought Delta ran a 717 on this route… Did they change it?
It changed to an A319. But mainly ERJs and CRJs are used.
My Best bet would have to be a United Express E Jet or CRJ
Take a look online at flight aware flight finder. (US only)