Got Neutral, but it was missing some utah valley isms that I'll slip into if careless.. for -> fer, creek -> crick, mountain -> mou'n (or other nt+vowel+n suffix, n and t are soft enough to not be there and the vowel is replaced by a pause; clinton -> cli-in/cli'n, mitten -> mih'n...), both -> bolth... The NYT one linked was interesting too, the heatmap included everything aligned and west of Utah minus Arizona, plus a bit of the northeast and great lakes areas. The NYT one was also interesting in that a few examples, like roundabout, had me think for a minute about what I'd say in a conversation vs what I expect to hear (traffic circle) in general from e.g. google maps and might say instead if primed with it.
That's interesting to me -- having grown up in south-central PA, all of those are things that I associate with a more Appalachian accent. I never would have guessed people "out west" in Utah would speak like that.
is for->fer Utah? I'm in Indiana, born on the West Coast, and I dont know where I picked that up. I have also started to morph "car" and similar in the direction of "kerr," and (most embarrassingly) instead of "robot" in conversation ill say "robit." I havent been able to find out from those around me, or hear the same changes.
No idea where it'd originate from, but in central Utah it's common. A few others I've remembered include (similar to fer) your -> yer, our -> are, really -> rilly, prescription -> perscription, sale -> sell.
Robit is pretty funny, like a frog? Haven't heard anything like that.
A random YouTube search shows what I'd consider representative for the area, at least around my age, only a couple of fers though. Overall fairly "neutral". https://youtube.com/watch?v=k3IdMkc-aD4 Your sibling mentioned a similarity with Appalachian people, maybe some of it is a mountain thing, though if they had in mind anything like https://youtube.com/watch?v=Bn8O6Nx3C6w I don't really hear much similarity.